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1.
Curr Opin Pediatr ; 33(6): 570-575, 2021 12 01.
Article in English | MEDLINE | ID: mdl-34636348

ABSTRACT

PURPOSE OF REVIEW: The purpose of this review is to describe recent findings on the clinical presentation, pathogenesis, and management of fetal alcohol spectrum disorders (FASDs). Alcohol causes a range of physical, developmental, and cognitive impairments on the developing fetus. Individuals exposed to alcohol prenatally have a wide variability in dysmorphic and neurologic features. Hence, a greater understanding of the mechanisms through which alcohol induces defects in the developing fetus is imperative in developing therapies that prevent alcohol-induced effects. RECENT FINDINGS: Current research has focused on leveraging technology to developing tools that can aid in the diagnostic process, defining patterns of neurocognition and neuroimaging specific to FASD, developing neurobehavioral and pharmacologic interventions, and expanding access to care. SUMMARY: FASDs are a common cause of neurodevelopmental impairment in school-age children, and their recognition is essential to provide early interventions in order to optimize the outcome for these individuals when they reach adulthood. Although previously thought to be the result of irreversible neurologic injury from prenatal alcohol exposure, recent evidence points to the benefits of applying principles regarding neuroplasticity in improving the lives for patients and their families.


Subject(s)
Fetal Alcohol Spectrum Disorders , Prenatal Exposure Delayed Effects , Adult , Child , Female , Fetal Alcohol Spectrum Disorders/diagnosis , Fetal Alcohol Spectrum Disorders/therapy , Humans , Pregnancy , Prenatal Exposure Delayed Effects/diagnosis
2.
Hum Genet ; 140(12): 1709-1731, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34652576

ABSTRACT

Microtubules are formed from heterodimers of alpha- and beta-tubulin, each of which has multiple isoforms encoded by separate genes. Pathogenic missense variants in multiple different tubulin isoforms cause brain malformations. Missense mutations in TUBB3, which encodes the neuron-specific beta-tubulin isotype, can cause congenital fibrosis of the extraocular muscles type 3 (CFEOM3) and/or malformations of cortical development, with distinct genotype-phenotype correlations. Here, we report fourteen individuals from thirteen unrelated families, each of whom harbors the identical NM_006086.4 (TUBB3):c.785G>A (p.Arg262His) variant resulting in a phenotype we refer to as the TUBB3 R262H syndrome. The affected individuals present at birth with ptosis, ophthalmoplegia, exotropia, facial weakness, facial dysmorphisms, and, in most cases, distal congenital joint contractures, and subsequently develop intellectual disabilities, gait disorders with proximal joint contractures, Kallmann syndrome (hypogonadotropic hypogonadism and anosmia), and a progressive peripheral neuropathy during the first decade of life. Subsets may also have vocal cord paralysis, auditory dysfunction, cyclic vomiting, and/or tachycardia at rest. All fourteen subjects share a recognizable set of brain malformations, including hypoplasia of the corpus callosum and anterior commissure, basal ganglia malformations, absent olfactory bulbs and sulci, and subtle cerebellar malformations. While similar, individuals with the TUBB3 R262H syndrome can be distinguished from individuals with the TUBB3 E410K syndrome by the presence of congenital and acquired joint contractures, an earlier onset peripheral neuropathy, impaired gait, and basal ganglia malformations.


Subject(s)
Facial Paralysis/genetics , Fibrosis/genetics , Mutation , Ophthalmoplegia/genetics , Peripheral Nervous System Diseases/genetics , Tubulin/genetics , Abnormalities, Multiple/genetics , Adolescent , Adult , Amino Acid Substitution , Arginine , Child , Child, Preschool , Facial Paralysis/diagnosis , Facial Paralysis/physiopathology , Female , Fibrosis/diagnosis , Fibrosis/physiopathology , Histidine , Humans , Infant , Male , Ophthalmoplegia/diagnosis , Ophthalmoplegia/physiopathology , Peripheral Nervous System Diseases/diagnosis , Peripheral Nervous System Diseases/physiopathology , Syndrome , Young Adult
3.
Am J Med Genet A ; 182(12): 2939-2950, 2020 12.
Article in English | MEDLINE | ID: mdl-32985117

ABSTRACT

Rubinstein-Taybi syndrome (RSTS) is an autosomal dominant disorder, caused by loss-of-function variants in CREBBP or EP300. Affected individuals present with distinctive craniofacial features, broad thumbs and/or halluces, and intellectual disability. RSTS phenotype has been well characterized in individuals of European descent but not in other populations. In this study, individuals from diverse populations with RSTS were assessed by clinical examination and facial analysis technology. Clinical data of 38 individuals from 14 different countries were analyzed. The median age was 7 years (age range: 7 months to 47 years), and 63% were females. The most common phenotypic features in all population groups included broad thumbs and/or halluces in 97%, convex nasal ridge in 94%, and arched eyebrows in 92%. Face images of 87 individuals with RSTS (age range: 2 months to 47 years) were collected for evaluation using facial analysis technology. We compared images from 82 individuals with RSTS against 82 age- and sex-matched controls and obtained an area under the receiver operating characteristic curve (AUC) of 0.99 (p < .001), demonstrating excellent discrimination efficacy. The discrimination was, however, poor in the African group (AUC: 0.79; p = .145). Individuals with EP300 variants were more effectively discriminated (AUC: 0.95) compared with those with CREBBP variants (AUC: 0.93). This study shows that clinical examination combined with facial analysis technology may enable earlier and improved diagnosis of RSTS in diverse populations.


Subject(s)
E1A-Associated p300 Protein/genetics , Ethnicity/genetics , Face/abnormalities , Genetics, Population , Mutation , Rubinstein-Taybi Syndrome/epidemiology , Adolescent , Adult , Case-Control Studies , Child , Child, Preschool , Cohort Studies , Female , Genetic Association Studies , Humans , Infant , International Agencies , Male , Middle Aged , Prognosis , Rubinstein-Taybi Syndrome/genetics , Rubinstein-Taybi Syndrome/pathology , Young Adult
4.
Am J Med Genet A ; 182(10): 2243-2252, 2020 10.
Article in English | MEDLINE | ID: mdl-32677343

ABSTRACT

Fetal alcohol spectrum disorders (FASD) describe a range of physical, behavioral, and neurologic deficits in individuals exposed to alcohol prenatally. Reduced palpebral fissure length is one of the cardinal facial features of FASD. However, other ocular measurements have not been studied extensively in FASD. Using the Fetal Alcohol Syndrome Epidemiologic Research (FASER) database, we investigated how inner canthal distance (ICD), interpupillary distance (IPD), and outer canthal distance (OCD) centiles differed between FASD and non-FASD individuals. We compared ocular measurement centiles in children with FASD to non-FASD individuals and observed reductions in all three centiles for ICD, IPD, and OCD. However, when our non-FASD children who had various forms of growth deficiency (microcephaly, short-stature, or underweight) were compared to controls, we did not observe a similar reduction in ocular measurements. This suggests that reductions in ocular measurements are a direct effect of alcohol on ocular development independent of its effect on growth parameters, which is consistent with animal models showing a negative effect of alcohol on developing neural crest cells. Interpupillary distance centile appeared to be the most significantly reduced ocular measure we evaluated, suggesting it may be a useful measure to be considered in the diagnosis of FASD.


Subject(s)
Alcohol Drinking/genetics , Fetal Alcohol Spectrum Disorders/genetics , Microcephaly/genetics , Neural Crest/growth & development , Alcohol Drinking/adverse effects , Alcohol Drinking/epidemiology , Animals , Child , Eye/metabolism , Eye/pathology , Face/pathology , Female , Fetal Alcohol Spectrum Disorders/epidemiology , Fetal Alcohol Spectrum Disorders/etiology , Fetal Alcohol Spectrum Disorders/pathology , Humans , Male , Maternal-Fetal Exchange/genetics , Microcephaly/chemically induced , Microcephaly/epidemiology , Neural Crest/pathology , Pregnancy
5.
Am J Med Genet A ; 182(9): 2021-2026, 2020 09.
Article in English | MEDLINE | ID: mdl-32524756

ABSTRACT

Angelman syndrome (AS) is caused by several genetic mechanisms that impair the expression of maternally-inherited UBE3A through deletions, paternal uniparental disomy (UPD), UBE3A pathogenic variants, or imprinting defects. Current methods of differentiating the etiology require molecular testing, which is sometimes difficult to obtain. Recently, computer-based facial analysis systems have been used to assist in identifying genetic conditions based on facial phenotypes. We sought to understand if the facial-recognition system DeepGestalt could find differences in phenotype between molecular subtypes of AS. Images and molecular data on 261 individuals with AS ranging from 10 months through 32 years were analyzed by DeepGestalt in a cross-validation model with receiver operating characteristic (ROC) curves generated. The area under the curve (AUC) of the ROC for each molecular subtype was compared and ranked from least to greatest differentiable phenotype. We determined that DeepGestalt demonstrated a high degree of discrimination between the deletion subtype and UPD or imprinting defects, and a lower degree of discrimination with the UBE3A pathogenic variants subtype. Our findings suggest that DeepGestalt can recognize subclinical differences in phenotype based on etiology and may provide decision support for testing.


Subject(s)
Angelman Syndrome/genetics , Deep Learning , Genomic Imprinting/genetics , Uniparental Disomy/genetics , Adolescent , Adult , Angelman Syndrome/classification , Angelman Syndrome/diagnosis , Angelman Syndrome/pathology , Child , Child, Preschool , Face/pathology , Female , Humans , Infant , Male , Maternal Inheritance/genetics , Phenotype , Ubiquitin-Protein Ligases/genetics , Uniparental Disomy/diagnosis , Uniparental Disomy/pathology , Young Adult
6.
Pediatrics ; 140(6)2017 Dec.
Article in English | MEDLINE | ID: mdl-29187580

ABSTRACT

OBJECTIVES: To compare the detection of facial attributes by computer-based facial recognition software of 2-D images against standard, manual examination in fetal alcohol spectrum disorders (FASD). METHODS: Participants were gathered from the Fetal Alcohol Syndrome Epidemiology Research database. Standard frontal and oblique photographs of children were obtained during a manual, in-person dysmorphology assessment. Images were submitted for facial analysis conducted by the facial dysmorphology novel analysis technology (an automated system), which assesses ratios of measurements between various facial landmarks to determine the presence of dysmorphic features. Manual blinded dysmorphology assessments were compared with those obtained via the computer-aided system. RESULTS: Areas under the curve values for individual receiver-operating characteristic curves revealed the computer-aided system (0.88 ± 0.02) to be comparable to the manual method (0.86 ± 0.03) in detecting patients with FASD. Interestingly, cases of alcohol-related neurodevelopmental disorder (ARND) were identified more efficiently by the computer-aided system (0.84 ± 0.07) in comparison to the manual method (0.74 ± 0.04). A facial gestalt analysis of patients with ARND also identified more generalized facial findings compared to the cardinal facial features seen in more severe forms of FASD. CONCLUSIONS: We found there was an increased diagnostic accuracy for ARND via our computer-aided method. As this category has been historically difficult to diagnose, we believe our experiment demonstrates that facial dysmorphology novel analysis technology can potentially improve ARND diagnosis by introducing a standardized metric for recognizing FASD-associated facial anomalies. Earlier recognition of these patients will lead to earlier intervention with improved patient outcomes.


Subject(s)
Biometric Identification/methods , Fetal Alcohol Spectrum Disorders/diagnosis , Child , Child, Preschool , Computers , Databases, Factual , Face , Female , Humans , Male , ROC Curve
7.
Brain ; 140(11): 2838-2850, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-29088354

ABSTRACT

The presynaptic, high-affinity choline transporter is a critical determinant of signalling by the neurotransmitter acetylcholine at both central and peripheral cholinergic synapses, including the neuromuscular junction. Here we describe an autosomal recessive presynaptic congenital myasthenic syndrome presenting with a broad clinical phenotype due to homozygous choline transporter missense mutations. The clinical phenotype ranges from the classical presentation of a congenital myasthenic syndrome in one patient (p.Pro210Leu), to severe neurodevelopmental delay with brain atrophy (p.Ser94Arg) and extend the clinical outcomes to a more severe spectrum with infantile lethality (p.Val112Glu). Cells transfected with mutant transporter construct revealed a virtually complete loss of transport activity that was paralleled by a reduction in transporter cell surface expression. Consistent with these findings, studies to determine the impact of gene mutations on the trafficking of the Caenorhabditis elegans choline transporter orthologue revealed deficits in transporter export to axons and nerve terminals. These findings contrast with our previous findings in autosomal dominant distal hereditary motor neuropathy of a dominant-negative frameshift mutation at the C-terminus of choline transporter that was associated with significantly reduced, but not completely abrogated choline transporter function. Together our findings define divergent neuropathological outcomes arising from different classes of choline transporter mutation with distinct disease processes and modes of inheritance. These findings underscore the essential role played by the choline transporter in sustaining acetylcholine neurotransmission at both central and neuromuscular synapses, with important implications for treatment and drug selection.


Subject(s)
Brain/pathology , Mutation, Missense , Myasthenic Syndromes, Congenital/genetics , Neurodevelopmental Disorders/genetics , Symporters/genetics , Animals , Animals, Genetically Modified , Atrophy , Axons/metabolism , Caenorhabditis elegans , Caenorhabditis elegans Proteins/genetics , Child, Preschool , Female , HEK293 Cells , Homozygote , Humans , Infant , Male , Membrane Transport Proteins/genetics , Pedigree , Presynaptic Terminals/metabolism , Protein Transport , Symporters/metabolism
8.
JCI Insight ; 2(16)2017 Aug 17.
Article in English | MEDLINE | ID: mdl-28814660

ABSTRACT

BACKGROUND: Cross-reactive immunological material-negative (CRIM-negative) infantile Pompe disease (IPD) patients develop an immune response against enzyme replacement therapy (ERT) with alglucosidase alfa that nullifies ERT efficacy. Prophylactic immune tolerance induction (ITI) with rituximab, methotrexate, and IVIG successfully prevents development of deleterious rhGAA IgG antibodies; however, safety, likelihood of success, and long-term efficacy of ITI in a larger cohort remain unknown. METHODS: Clinical data were analyzed for 19 CRIM-negative IPD patients who received ITI with rituximab, methotrexate, and IVIG in the ERT-naive setting (ERT+ITI) and compared to a historical cohort of 10 CRIM-negative IPD patients on ERT monotherapy. RESULTS: ITI was safely tolerated, although infections were reported in 4 patients. Fourteen (74%) ERT+ITI patients were alive, with a median age of 44.2 months at their final assessment. The eldest survivor was 103.9 months old, with 100.2 months of follow-up after initiation of ERT+ITI. Death (n = 5) occurred at a median age of 29.2 months and was unrelated to the administration of ITI. Fifteen patients either did not seroconvert (n = 8) or maintained low titers (n = 7; defined as titers of ≤6,400 throughout the course of ERT) following ERT+ITI. Only one patient developed high and sustained antibody titers (defined as titers of ≥51,200 at or beyond 6 months on ERT). Left ventricular mass index (LVMI) decreased from a median of 248.5 g/m2 at baseline to 76.8 g/m2 at a median time from ERT+ITI initiation to 59 weeks. ERT+ITI significantly improved overall survival (P = 0.001), eliminated/reduced antibodies at values of ≤6,400 at week 52 on ERT (P = 0.0004), and improved LVMI at week 52 on ERT (P = 0.02) when compared with ERT monotherapy. CONCLUSION: Evidence from this international cohort of CRIM-negative IPD patients further supports the safety, feasibility, and efficacy of ITI in the prevention of immune responses to ERT. TRIAL REGISTRATION: Clinicaltrials.gov NCT01665326. FUNDING: This research was supported in part by the Lysosomal Disease Network, a part of NIH Rare Diseases Clinical Research Network, and by a grant from Genzyme, a Sanofi company.

9.
Am J Med Genet A ; 173(9): 2323-2334, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28748642

ABSTRACT

Noonan syndrome (NS) is a common genetic syndrome associated with gain of function variants in genes in the Ras/MAPK pathway. The phenotype of NS has been well characterized in populations of European descent with less attention given to other groups. In this study, individuals from diverse populations with NS were evaluated clinically and by facial analysis technology. Clinical data and images from 125 individuals with NS were obtained from 20 countries with an average age of 8 years and female composition of 46%. Individuals were grouped into categories of African descent (African), Asian, Latin American, and additional/other. Across these different population groups, NS was phenotypically similar with only 2 of 21 clinical elements showing a statistically significant difference. The most common clinical characteristics found in all population groups included widely spaced eyes and low-set ears in 80% or greater of participants, short stature in more than 70%, and pulmonary stenosis in roughly half of study individuals. Using facial analysis technology, we compared 161 Caucasian, African, Asian, and Latin American individuals with NS with 161 gender and age matched controls and found that sensitivity was equal to or greater than 94% for all groups, and specificity was equal to or greater than 90%. In summary, we present consistent clinical findings from global populations with NS and additionally demonstrate how facial analysis technology can support clinicians in making accurate NS diagnoses. This work will assist in earlier detection and in increasing recognition of NS throughout the world.


Subject(s)
Face/physiopathology , Genetics, Population , Noonan Syndrome/genetics , Asian People , Black People/genetics , Child , Female , Humans , Male , Mitogen-Activated Protein Kinase Kinases/genetics , Noonan Syndrome/physiopathology , Signal Transduction , White People/genetics , ras Proteins/genetics
10.
J Pediatr Hematol Oncol ; 39(7): 573-575, 2017 10.
Article in English | MEDLINE | ID: mdl-28697167

ABSTRACT

Congenital amegakaryocytic thrombocytopenia is a rare disorder causing thrombocytopenia that progresses to pancytopenia and bone marrow failure if untreated. It is caused by variants in the MPL gene which encodes the thrombopoeitin receptor. In this report, we review 5 cases of congenital amegakaryocytic thrombocytopenia, all of whom belong to the Mississippi Band of Choctaw Indians. There are 2 common variants in these cases: R90X and R537W. One variant was previously reported only once and had unclear significance at that time. With these variants identified, we hope to improve screening that results in earlier diagnosis in the Choctaw population in the future.


Subject(s)
Indians, North American/genetics , Thrombocytopenia/genetics , Child , Child, Preschool , Congenital Bone Marrow Failure Syndromes , Female , Founder Effect , Genetic Variation , Humans , Infant, Newborn , Male , Mississippi , Receptors, Thrombopoietin/genetics , Thrombocytopenia/ethnology
11.
Am J Med Genet A ; 173(4): 879-888, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28328118

ABSTRACT

22q11.2 deletion syndrome (22q11.2 DS) is the most common microdeletion syndrome and is underdiagnosed in diverse populations. This syndrome has a variable phenotype and affects multiple systems, making early recognition imperative. In this study, individuals from diverse populations with 22q11.2 DS were evaluated clinically and by facial analysis technology. Clinical information from 106 individuals and images from 101 were collected from individuals with 22q11.2 DS from 11 countries; average age was 11.7 and 47% were male. Individuals were grouped into categories of African descent (African), Asian, and Latin American. We found that the phenotype of 22q11.2 DS varied across population groups. Only two findings, congenital heart disease and learning problems, were found in greater than 50% of participants. When comparing the clinical features of 22q11.2 DS in each population, the proportion of individuals within each clinical category was statistically different except for learning problems and ear anomalies (P < 0.05). However, when Africans were removed from analysis, six additional clinical features were found to be independent of ethnicity (P ≥ 0.05). Using facial analysis technology, we compared 156 Caucasians, Africans, Asians, and Latin American individuals with 22q11.2 DS with 156 age and gender matched controls and found that sensitivity and specificity were greater than 96% for all populations. In summary, we present the varied findings from global populations with 22q11.2 DS and demonstrate how facial analysis technology can assist clinicians in making accurate 22q11.2 DS diagnoses. This work will assist in earlier detection and in increasing recognition of 22q11.2 DS throughout the world.


Subject(s)
Biometric Identification/methods , DiGeorge Syndrome/diagnosis , Heart Defects, Congenital/diagnosis , Image Interpretation, Computer-Assisted/methods , Learning Disabilities/diagnosis , Adolescent , Adult , Asian People , Black People , Child , Child, Preschool , Chromosomes, Human, Pair 22/chemistry , DiGeorge Syndrome/ethnology , DiGeorge Syndrome/genetics , DiGeorge Syndrome/pathology , Facies , Female , Heart Defects, Congenital/ethnology , Heart Defects, Congenital/genetics , Heart Defects, Congenital/pathology , Hispanic or Latino , Humans , In Situ Hybridization, Fluorescence , Infant , Infant, Newborn , Learning Disabilities/ethnology , Learning Disabilities/genetics , Learning Disabilities/physiopathology , Male , Phenotype , White People
12.
Am J Med Genet A ; 173(1): 42-53, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27991738

ABSTRACT

Down syndrome is the most common cause of cognitive impairment and presents clinically with universally recognizable signs and symptoms. In this study, we focus on exam findings and digital facial analysis technology in individuals with Down syndrome in diverse populations. Photos and clinical information were collected on 65 individuals from 13 countries, 56.9% were male and the average age was 6.6 years (range 1 month to 26 years; SD = 6.6 years). Subjective findings showed that clinical features were different across ethnicities (Africans, Asians, and Latin Americans), including brachycephaly, ear anomalies, clinodactyly, sandal gap, and abundant neck skin, which were all significantly less frequent in Africans (P < 0.001, P < 0.001, P < 0.001, P < 0.05, and P < 0.05, respectively). Evaluation using a digital facial analysis technology of a larger diverse cohort of newborns to adults (n = 129 cases; n = 132 controls) was able to diagnose Down syndrome with a sensitivity of 0.961, specificity of 0.924, and accuracy of 0.943. Only the angles at medial canthus and ala of the nose were common significant findings amongst different ethnicities (Caucasians, Africans, and Asians) when compared to ethnically matched controls. The Asian group had the least number of significant digital facial biometrics at 4, compared to Caucasians at 8 and Africans at 7. In conclusion, this study displays the wide variety of findings across different geographic populations in Down syndrome and demonstrates the accuracy and promise of digital facial analysis technology in the diagnosis of Down syndrome internationally. © 2016 Wiley Periodicals, Inc.


Subject(s)
Down Syndrome/diagnosis , Down Syndrome/epidemiology , Facies , Genetic Association Studies , Phenotype , Population Groups/statistics & numerical data , Population Surveillance , Adolescent , Adult , Biomarkers , Case-Control Studies , Child , Child, Preschool , Down Syndrome/genetics , Female , Humans , Infant , Infant, Newborn , Male , Population Groups/genetics , Sensitivity and Specificity , Young Adult
13.
Nat Genet ; 49(1): 36-45, 2017 01.
Article in English | MEDLINE | ID: mdl-27841880

ABSTRACT

Despite the clinical significance of balanced chromosomal abnormalities (BCAs), their characterization has largely been restricted to cytogenetic resolution. We explored the landscape of BCAs at nucleotide resolution in 273 subjects with a spectrum of congenital anomalies. Whole-genome sequencing revised 93% of karyotypes and demonstrated complexity that was cryptic to karyotyping in 21% of BCAs, highlighting the limitations of conventional cytogenetic approaches. At least 33.9% of BCAs resulted in gene disruption that likely contributed to the developmental phenotype, 5.2% were associated with pathogenic genomic imbalances, and 7.3% disrupted topologically associated domains (TADs) encompassing known syndromic loci. Remarkably, BCA breakpoints in eight subjects altered a single TAD encompassing MEF2C, a known driver of 5q14.3 microdeletion syndrome, resulting in decreased MEF2C expression. We propose that sequence-level resolution dramatically improves prediction of clinical outcomes for balanced rearrangements and provides insight into new pathogenic mechanisms, such as altered regulation due to changes in chromosome topology.


Subject(s)
Chromosome Aberrations , Congenital Abnormalities/genetics , Gene Rearrangement , Genetic Markers/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Female , Humans , Male
14.
Genome Med ; 8(1): 106, 2016 11 01.
Article in English | MEDLINE | ID: mdl-27799064

ABSTRACT

BACKGROUND: Mitochondrial presequence proteases perform fundamental functions as they process about 70 % of all mitochondrial preproteins that are encoded in the nucleus and imported posttranslationally. The mitochondrial intermediate presequence protease MIP/Oct1, which carries out precursor processing, has not yet been established to have a role in human disease. METHODS: Whole exome sequencing was performed on four unrelated probands with left ventricular non-compaction (LVNC), developmental delay (DD), seizures, and severe hypotonia. Proposed pathogenic variants were confirmed by Sanger sequencing or array comparative genomic hybridization. Functional analysis of the identified MIP variants was performed using the model organism Saccharomyces cerevisiae as the protein and its functions are highly conserved from yeast to human. RESULTS: Biallelic single nucleotide variants (SNVs) or copy number variants (CNVs) in MIPEP, which encodes MIP, were present in all four probands, three of whom had infantile/childhood death. Two patients had compound heterozygous SNVs (p.L582R/p.L71Q and p.E602*/p.L306F) and one patient from a consanguineous family had a homozygous SNV (p.K343E). The fourth patient, identified through the GeneMatcher tool, a part of the Matchmaker Exchange Project, was found to have inherited a paternal SNV (p.H512D) and a maternal CNV (1.4-Mb deletion of 13q12.12) that includes MIPEP. All amino acids affected in the patients' missense variants are highly conserved from yeast to human and therefore S. cerevisiae was employed for functional analysis (for p.L71Q, p.L306F, and p.K343E). The mutations p.L339F (human p.L306F) and p.K376E (human p.K343E) resulted in a severe decrease of Oct1 protease activity and accumulation of non-processed Oct1 substrates and consequently impaired viability under respiratory growth conditions. The p.L83Q (human p.L71Q) failed to localize to the mitochondria. CONCLUSIONS: Our findings reveal for the first time the role of the mitochondrial intermediate peptidase in human disease. Loss of MIP function results in a syndrome which consists of LVNC, DD, seizures, hypotonia, and cataracts. Our approach highlights the power of data exchange and the importance of an interrelationship between clinical and research efforts for disease gene discovery.


Subject(s)
Genes, Recessive/genetics , Heart Defects, Congenital/etiology , Metalloendopeptidases/genetics , Muscle Hypotonia/etiology , Sudden Infant Death/etiology , Adult , Amino Acid Sequence , Female , Humans , Infant , Infant, Newborn , Male , Pedigree , Phenotype , Sequence Homology, Amino Acid , Syndrome
15.
Cold Spring Harb Mol Case Stud ; 2(1): a000661, 2016 Jan.
Article in English | MEDLINE | ID: mdl-27148580

ABSTRACT

We identified five unrelated individuals with significant global developmental delay and intellectual disability (ID), dysmorphic facial features and frequent microcephaly, and de novo predicted loss-of-function variants in chromosome alignment maintaining phosphoprotein 1 (CHAMP1). Our findings are consistent with recently reported de novo mutations in CHAMP1 in five other individuals with similar features. CHAMP1 is a zinc finger protein involved in kinetochore-microtubule attachment and is required for regulating the proper alignment of chromosomes during metaphase in mitosis. Mutations in CHAMP1 may affect cell division and hence brain development and function, resulting in developmental delay and ID.

16.
Birth Defects Res A Clin Mol Teratol ; 106(1): 47-54, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26407522

ABSTRACT

BACKGROUND: The National Children's Study (NCS) Vanguard Study began enrollment in January 2009 as an initial pilot study for a planned large-scale, longitudinal U.S. cohort study of the effect of environmental influences on child health and development, with biological and environmental sample collection conducted in seven locations from April 2009 to October 2010. We sought to determine rates of consent for, and success of collection of, maternal and paternal biospecimens before and during pregnancy in the NCS Vanguard Study. METHODS: Samples of blood, saliva, vaginal swabs, urine, hair, and nails were collected before and during pregnancy. All specimens were sent to a central repository for processing, storage, and quality assessment. RESULTS: Of 780 pregnant women asked to consent to sample collection, 773 (>99%) agreed, and of 295 nonpregnant women, 292 (99%) agreed. Of 440 fathers asked to consent to sample collection, 435 (99%) agreed. Frequency of successful collection of biospecimens varied depending on sample and visit type. In descending order, the ranges over all visit types of the proportion of expected samples successfully collected from women were: urine, 92.5 to 95.7%; hair, 89.6 to 92.5%; vaginal swab, 84.2 to 88.5%; blood, 74.9 to 78.5%; 2-day saliva, 65.8 to 81.6%; and nails, 76.4 to 76.7%. For fathers, rates were highest for urine (94.9%) and lowest for hair (63.0%). CONCLUSION: High rates of consent for and collection of a wide variety of biospecimens can be achieved in prospective epidemiologic cohort studies of pregnant women. Ease of sample collection may be a primary factor influencing successful biospecimen collection.


Subject(s)
Informed Consent/statistics & numerical data , Prenatal Diagnosis , Specimen Handling/statistics & numerical data , Adult , Child , Epidemiologic Studies , Family Characteristics , Female , Health Surveys , Humans , Male , Pregnancy , Pregnancy Trimesters , United States
17.
Eur J Hum Genet ; 24(5): 652-9, 2016 May.
Article in English | MEDLINE | ID: mdl-26306646

ABSTRACT

The Koolen-de Vries syndrome (KdVS; OMIM #610443), also known as the 17q21.31 microdeletion syndrome, is a clinically heterogeneous disorder characterised by (neonatal) hypotonia, developmental delay, moderate intellectual disability, and characteristic facial dysmorphism. Expressive language development is particularly impaired compared with receptive language or motor skills. Other frequently reported features include social and friendly behaviour, epilepsy, musculoskeletal anomalies, congenital heart defects, urogenital malformations, and ectodermal anomalies. The syndrome is caused by a truncating variant in the KAT8 regulatory NSL complex unit 1 (KANSL1) gene or by a 17q21.31 microdeletion encompassing KANSL1. Herein we describe a novel cohort of 45 individuals with KdVS of whom 33 have a 17q21.31 microdeletion and 12 a single-nucleotide variant (SNV) in KANSL1 (19 males, 26 females; age range 7 months to 50 years). We provide guidance about the potential pitfalls in the laboratory testing and emphasise the challenges of KANSL1 variant calling and DNA copy number analysis in the complex 17q21.31 region. Moreover, we present detailed phenotypic information, including neuropsychological features, that contribute to the broad phenotypic spectrum of the syndrome. Comparison of the phenotype of both the microdeletion and SNV patients does not show differences of clinical importance, stressing that haploinsufficiency of KANSL1 is sufficient to cause the full KdVS phenotype.


Subject(s)
Abnormalities, Multiple/diagnosis , Intellectual Disability/diagnosis , Nuclear Proteins/genetics , Phenotype , Polymorphism, Single Nucleotide , Abnormalities, Multiple/genetics , Adolescent , Adult , Child , Chromosome Deletion , Chromosomes, Human, Pair 17/genetics , Female , Humans , Intellectual Disability/genetics , Male , Middle Aged
18.
Nat Genet ; 47(8): 926-32, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26168012

ABSTRACT

Dominant optic atrophy (DOA) and axonal peripheral neuropathy (Charcot-Marie-Tooth type 2, or CMT2) are hereditary neurodegenerative disorders most commonly caused by mutations in the canonical mitochondrial fusion genes OPA1 and MFN2, respectively. In yeast, homologs of OPA1 (Mgm1) and MFN2 (Fzo1) work in concert with Ugo1, for which no human equivalent has been identified thus far. By whole-exome sequencing of patients with optic atrophy and CMT2, we identified four families with recessive mutations in SLC25A46. We demonstrate that SLC25A46, like Ugo1, is a modified carrier protein that has been recruited to the outer mitochondrial membrane and interacts with the inner membrane remodeling protein mitofilin (Fcj1). Loss of function in cultured cells and in zebrafish unexpectedly leads to increased mitochondrial connectivity, while severely affecting the development and maintenance of neurons in the fish. The discovery of SLC25A46 strengthens the genetic overlap between optic atrophy and CMT2 while exemplifying a new class of modified solute transporters linked to mitochondrial dynamics.


Subject(s)
Genetic Predisposition to Disease/genetics , Mitochondrial Proteins/genetics , Mutation , Optic Atrophy, Autosomal Dominant/genetics , Phosphate Transport Proteins/genetics , Animals , Animals, Genetically Modified , COS Cells , Charcot-Marie-Tooth Disease/genetics , Charcot-Marie-Tooth Disease/metabolism , Chlorocebus aethiops , Embryo, Nonmammalian/embryology , Embryo, Nonmammalian/metabolism , Embryo, Nonmammalian/ultrastructure , Exome/genetics , Female , HEK293 Cells , Humans , Male , Membrane Proteins/genetics , Membrane Proteins/metabolism , Microscopy, Confocal , Microscopy, Electron, Transmission , Mitochondrial Membranes/metabolism , Mitochondrial Proteins/metabolism , Muscle Proteins/genetics , Muscle Proteins/metabolism , Optic Atrophy, Autosomal Dominant/metabolism , Optic Atrophy, Autosomal Dominant/pathology , Pedigree , Phosphate Transport Proteins/metabolism , Protein Binding , RNA Interference , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , Sequence Analysis, DNA , Zebrafish/embryology , Zebrafish/metabolism
19.
Clin Infect Dis ; 59 Suppl 7: S428-36, 2014 Dec 15.
Article in English | MEDLINE | ID: mdl-25425721

ABSTRACT

In 2011 and 2012, the Division of Microbiology and Infectious Diseases at the National Institute of Allergy and Infectious Diseases, National Institutes of Health, held a series of meetings to provide guidance to investigators regarding study design of clinical trials of vaccines and antimicrobial medications that enroll pregnant women. Assessment of congenital anomalies among infants born to women enrolled in these trials was recognized as a challenging issue, and a workgroup with expertise in epidemiology, pediatrics, genetics, dysmorphology, clinical trials, and infectious diseases was formed to address this issue. The workgroup considered 3 approaches for congenital anomalies assessment that have been developed for use in other studies: (1) maternal report combined with medical records review, (2) standardized photographic assessment and physical examination by a health professional who has received specific training in congenital anomalies, and (3) standardized physical examination by a trained dysmorphologist (combined with maternal interview and medical records review). The strengths and limitations of these approaches were discussed with regard to their use in clinical trials. None of the approaches was deemed appropriate for use in all clinical trials. Instead, the workgroup acknowledged that decisions regarding the optimal method of assessment of congenital anomalies will likely vary depending on the clinical trial, its setting, and the agent under study; in some cases, a combination of approaches may be appropriate. The workgroup recognized the need for more research on approaches to the assessment of congenital anomalies to better guide investigators in optimal design of clinical trials that enroll pregnant women.


Subject(s)
Clinical Trials as Topic , Congenital Abnormalities , Pregnant Women , Anti-Infective Agents/administration & dosage , Congenital Abnormalities/diagnosis , Congenital Abnormalities/epidemiology , Female , Humans , Infant , Infant, Newborn , Pregnancy , United States , Vaccines/administration & dosage
20.
Pediatrics ; 133(1): e257-62, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24344107

ABSTRACT

Leukocyte adhesion deficiency (LAD) I is a well-described genetic disorder in which leukocytes are unable to migrate to sites of inflammation due to mutations in the ITGB2 gene coding for the ß subunit of ß2 (CD18) leukocyte integrins. The classic symptoms of the disease present in the newborn period as failure of separation of the umbilical cord and recurrent bacterial infections, which continue throughout life. We report on a patient with these clinical manifestations but with normal ITGB2 gene sequencing excluding LAD-I, normal carbohydrate-deficient transferrin testing excluding LAD-II, and normal platelet function excluding LAD-III. With testing for CD18 integrin function by flow cytometry, adhesion assay analysis, and time-lapse microscopy, we found the patient's T lymphocytes to express normal levels of ß1 and ß2 integrins but to be highly adhesive to integrin ligands and to display decreased migration compared with control T lymphocytes. The hyperadhesiveness of the cells suggests that they might be prevented from reaching infected tissues. Interestingly, administration of glucocorticoids, for the patient's nephrotic syndrome, alleviated the patient's chronic diarrhea and decreased the incidence of skin infections. The hyperadhesiveness rather than adhesion deficiency of the patient's leukocytes suggests that a novel lesion in a pathway regulating integrin adhesion is responsible for the patient's unique LAD-I-like symptoms.


Subject(s)
CD18 Antigens/genetics , Leukocyte-Adhesion Deficiency Syndrome/diagnosis , T-Lymphocytes/physiology , Biomarkers/metabolism , CD18 Antigens/metabolism , Cell Adhesion , Cell Movement , Child, Preschool , Diagnosis, Differential , Female , Genetic Markers , Humans , Leukocyte-Adhesion Deficiency Syndrome/complications , Leukocyte-Adhesion Deficiency Syndrome/genetics , Leukocyte-Adhesion Deficiency Syndrome/immunology , Nephrotic Syndrome/etiology , Skin Diseases, Bacterial/etiology , Umbilical Cord/physiopathology
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