Clinical characterizations and molecular genetic study of two co-segregating variants in PDZD7 and PDE6C genes leading simultaneously to non-syndromic hearing loss and achromatopsia.

BACKGROUND: Autosomal recessive non-syndromic hearing loss (NSHL) and cone dystrophies (CODs) are highly genetically and phenotypically heterogeneous disorders. In this study, we applied the whole exome sequencing (WES) to find the cause of HL and COD in an Iranian consanguineous family with three affected individuals. METHODS: Three members from an Iranian consanguineous family who were suffering from NSHL and visual impairment were ascertained in this study. Comprehensive clinical evaluations and genetic analysis followed by bioinformatic and co-segregation studies were performed to diagnose the cause of these phenotypes. Data were collected from 2020 to 2022. RESULTS: All cases showed congenital bilateral NSHL, decreased visual acuity, poor color discrimination, photophobia and macular atrophy. Moreover, cornea, iris and anterior vitreous were within normal limit in both eyes, decreased foveal sensitivity, central scotoma and generalized depression of visual field were seen in three cases. WES results showed two variants, a novel null variant (p.Trp548Ter) in the PDE6C gene causing COD type 4 (Achromatopsia) and a previously reported variant (p.Ile84Thr) in the PDZD7 gene causing NSHL. Both variants were found in the cis configuration on chromosome 10 with a genetic distance of about 8.3 cM, leading to their co-inheritance. However, two diseases could appear independently in subsequent generations due to crossover during meiosis. CONCLUSIONS: Here, we could successfully determine the etiology of a seemingly complex phenotype in two adjacent genes. We identified a novel variant in the PDE6C gene, related to achromatopsia. Interestingly, this variant could cooperatively cause visual disorders: cone dystrophy and cone-rod dystrophy.

A novel start-loss mutation of the SLC29A3 gene in a consanguineous family with H syndrome: clinical characteristics, in silico analysis and literature review.

BACKGROUND: The SLC29A3 gene, which encodes a nucleoside transporter protein, is primarily located in intracellular membranes. The mutations in this gene can give rise to various clinical manifestations, including H syndrome, dysosteosclerosis, Faisalabad histiocytosis, and pigmented hypertrichosis with insulin-dependent diabetes. The aim of this study is to present two Iranian patients with H syndrome and to describe a novel start-loss mutation in SLC29A3 gene. METHODS: In this study, we employed whole-exome sequencing (WES) as a method to identify genetic variations that contribute to the development of H syndrome in a 16-year-old girl and her 8-year-old brother. These siblings were part of an Iranian family with consanguineous parents. To confirmed the pathogenicity of the identified variant, we utilized in-silico tools and cross-referenced various databases to confirm its novelty. Additionally, we conducted a co-segregation study and verified the presence of the variant in the parents of the affected patients through Sanger sequencing. RESULTS: In our study, we identified a novel start-loss mutation (c.2T > A, p.Met1Lys) in the SLC29A3 gene, which was found in both of two patients. Co-segregation analysis using Sanger sequencing confirmed that this variant was inherited from the parents. To evaluate the potential pathogenicity and novelty of this mutation, we consulted various databases. Additionally, we employed bioinformatics tools to predict the three-dimensional structure of the mutant SLC29A3 protein. These analyses were conducted with the aim of providing valuable insights into the functional implications of the identified mutation on the structure and function of the SLC29A3 protein. CONCLUSION: Our study contributes to the expanding body of evidence supporting the association between mutations in the SLC29A3 gene and H syndrome. The molecular analysis of diseases related to SLC29A3 is crucial in understanding the range of variability and raising awareness of H syndrome, with the ultimate goal of facilitating early diagnosis and appropriate treatment. The discovery of this novel biallelic variant in the probands further underscores the significance of utilizing genetic testing approaches, such as WES, as dependable diagnostic tools for individuals with this particular condition.

Long-term health outcomes from inbreeding in a historical Swedish population: longevity, fertility, and impairments.

BACKGROUND: Inbreeding, arising from consanguinity between related parents, has been observed to impact the health of individuals, typically attributed to biological factors. Nevertheless, these effects may be influenced by the social and environmental conditions. The prevalence of consanguineous marriages increased in certain parts of Sweden after it became legal in 1844, which offers a unique opportunity to study and understand the effects of inbreeding on health. AIM: The objective of this study is to explore the potential impact of inbreeding on the longevity, fertility, and impairments of individuals born in the Skellefteå region, Sweden, between 1890 and 1905, with a follow-up period extending until 1950. SUBJECTS AND METHODS: The level of inbreeding is calculated using micro-level parish register data and related to longevity, fertility, and impairments using regression analysis. RESULTS: Inbreeding is shown to be associated with longevity, fertility, and impairments. It seems to affect the risk of stillbirth and impairments and male longevity and fertility. CONCLUSION: Inbreeding seems to have had a detrimental effect on some health outcomes in this historical population under study.

Health beliefs of unmarried adult Saudi individuals toward safe marriage and the role of premarital screening in avoiding consanguinity: a nationwide cross-sectional study.

Introduction: Premarital screening (PMS) is an essential global measure that seeks to reduce the occurrence of specific genetic disorders and sexually transmitted diseases common in consanguineous marriages. Due to the lack of a nationwide study, this research was designed to comprehend how unmarried individuals perceive the risks and benefits of PMS. Method: A cross-sectional study was conducted using an online questionnaire distributed through different social media platforms, responses from the native adult population (18-49 years) Saudi Arabia was only included in the study. The questionnaire was based on the Health Belief Model (HBM) to assessing seven different constructs including susceptibility, seriousness, benefits-, barriers-, & cues- to action, self-efficacy, and social acceptance. Data frequency was represented by mean and standard deviation; chi-square and t-tests were conducted for the comparison of independent and dependent variables. A multinomial logistic regression was used to predict factors influencing decisions related to PMS. Results: 1,522 participants completed the survey, mostly 18-25 years old and most of them were women. The majority were single with 85 men and 1,370 women. Most participants (59.6%) believed their parents were related, while 40.5% did not. 122 respondents reported they had to marry within their tribe. Findings revealed significant correlations among all HBM themes, with varying strengths. Notably, a moderate positive relationship was found between the perception of benefits and cues to action, suggesting that enhancing the perceived benefits of PMS could facilitate safe marriage practices. Multinomial regression analysis revealed that demographic factors and health beliefs significantly influence individuals' intentions and behaviors toward PMS and safe marriage. Conclusion: The study concludes that by identifying and addressing barriers, and promoting positive social acceptance, PMS can significantly contribute to preventing genetic diseases and promoting safe marriage practices, although the cross-sectional design limits the establishment of causal relationships and further research is needed.

Homozygous TNNI3 frameshift variant in a consanguineous family with lethal infantile dilated cardiomyopathy.

BACKGROUND: Dilated cardiomyopathy (DCM) is characterized by dilatation of the left ventricle, systolic dysfunction, and normal or reduced thickness of the left ventricular wall. It is a leading cause of heart failure and cardiac death at a young age. Cases with neonatal onset DCM were correlated with severe clinical presentation and poor prognosis. A monogenic molecular etiology accounts for nearly half of cases. FAMILY DESCRIPTION: Here, we report a family with three deceased offspring at the age of 1 year old. The autopsy of the first deceased infant revealed a DCM. The second infant presented a DCM phenotype with a severely reduced Left Ventricular Ejection Fraction (LVEF) of 10%. Similarly, the third infant showed a severe DCM phenotype with LVEF of 30% as well, in addition to eccentric mitral insufficiency. RESULTS: Exome sequencing was performed for the trio (the second deceased infant and her parents). Data analysis following the autosomal dominant and recessive patterns of inheritance was carried out along with a mitochondrial pathways-based analysis. We identified a homozygous frameshift variant in the TNNI3 gene (c.204delG; p.(Arg69AlafsTer8)). This variant has been recently reported in the ClinVar database in association with cardiac phenotypes as pathogenic or likely pathogenic and classified as pathogenic according to ACMG. CONCLUSION: Genetic counseling was provided for the family and a prenatal diagnosis of choronic villus was proposed in the absence of pre-implantation genetic diagnosis possibilities. Our study expands the case series of early-onset DCM patients with a protein-truncating variant in the TNNI3 gene by reporting three affected infant siblings.

SCAPER-Related Autosomal Recessive Retinitis Pigmentosa with Intellectual Disability: Confirming and Extending the Phenotypic Spectrum and Bioinformatics Analyses.

Mutations in the gene SCAPER (S phase Cyclin A-Associated Protein residing in the Endoplasmic Reticulum) have recently been associated with retinitis pigmentosa (RP) and intellectual disability (ID). In 2011, a possible involvement of SCAPER in human diseases was discovered for the first time due to the identification of a homozygous mutation causing ID in an Iranian family. Later, five studies were published in 2019 that described patients with autosomal recessive syndromic retinitis pigmentosa (arRP) accompanied by ID and attention-deficit/hyperactivity disorder (ADHD). This present study describes three patients from an Arab consanguineous family in Israel with similar clinical features of the SCAPER syndrome. In addition, new manifestations of ocular symptoms, nystagmus, glaucoma, and elevator palsy, were observed. Genetic testing of the patients and both parents via whole-exome sequencing revealed the homozygous mutation c.2023-2A>G in SCAPER. Phenotypic and genotypic descriptions for all available cases described in the literature including our current three cases (37 cases) were carried out, in addition to a bioinformatics analysis for all the genetic variants that was undertaken. Our study confirms and extends the clinical manifestations of SCAPER-related disorders.

Microcornea, cerebellar hypoplasia and hyperlax joints-unusual combo in rare Ehlers-Danlos syndrome-musculocontractural type 1.

Ehlers-Danlos syndrome is a group of connective tissue disorders with 14 subtypes, involving joint hyperlaxity, tissue fragility, hypertensive skin and other systemic organs with an incidence of 1 in 1 000 000 worldwide. We report a middle childhood female born of second degree consanguineous marriage with limping gait with muscle weakness, with normal development and IQ. Examination revealed microcornea, distal joint laxity of fingers and wrist, hypotonia and broad-based limping gait. Fracture dislocation right hip was managed by fixation. With the atypical neuroimaging finding of cerebellar vermis hypoplasia, exome sequencing was ordered and confirmed as Ehlers-Danlos syndrome (musculocontractural type-1). Hence, genetic counselling was done and prognosis of the child was explained.

Molecular genetics, neuroimaging outcomes, and structural analyses of novel and recurrent variants of WDR62 gene in two consanguineous Pakistani families with autosomal recessive primary microcephaly.

BACKGROUND: Autosomal recessive primary microcephaly (MCPH) is a rare neurodevelopmental and genetically heterogeneous disorder, characterized by small cranium size (> - 3 SD below mean) and often results in varying degree of intellectual disability. Thirty genes have been identified for the etiology of this disorder due to its clinical and genetic heterogeneity. METHODS AND RESULTS: Here, we report two consanguineous Pakistani families affected with MCPH exhibiting mutation in WDR62 gene. The investigation approach involved Next Generation Sequencing (NGS) gene panel sequencing coupled with linkage analysis followed by validation of identified variants through automated Sanger sequencing and Barcode-Tagged (BT) sequencing. The molecular genetic analysis revealed one novel splice site variant (NM_001083961.2(WDR62):c.1372-1del) in Family A and one known exonic variant NM_001083961.2(WDR62):c.3936dup (p.Val1313Argfs*18) in Family B. Magnetic Resonance Imaging (MRI) scans were also employed to gain insights into the structural architecture of affected individuals. Neurological assessments showed the reduced gyral and sulcal patterns along with normal corpus callosum in affected individuals harboring novel variant. In silico assessments of the identified variants were conducted using different tools to confirm the pathogenicity of these variants. Through In silico analyses, both variants were identified as disease causing and protein modeling of exonic variant indicates subtle conformational alterations in prophesied protein structure. CONCLUSION: This study identifies a novel variant (c.1372-1del) and a recurrent pathogenic variant c.3936dup (p.Val1313Argfs*18) in the WDR62 gene among the Pakistani population, expanding the mutation spectrum for MCPH. These findings emphasize the importance of genetic counseling and awareness to reduce consanguinity and address the burden of this disorder.

Homozygous TREM2 c.549del; p.(Leu184Serfs*5) variant causing Nasu-Hakola disease in three siblings in a consanguineous Iraqi family: Case report and review of literature.

BACKGROUND: The Triggering Receptor Expressed on Myeloid Cells 2 protein (TREM2) plays a crucial role in various biological processes, including osteoclast differentiation, and disease-associated microglia (DAM) activation to regulate neuroinflammation, and phagocytosis in the brain. Genetic variations in TREM2 are implicated in neurodegenerative disorders, such as Nasu-hakola disease (NHD), characterized by bone lesions, neuropsychiatric disorders, and early-onset dementia. METHODS: We studied 3 siblings with suspected NHD. Whole-exome sequencing was conducted on the proband to identify the possible genetic cause(s) and by Sanger sequencing to validate the identified variants in the two other affected siblings, a healthy sister, and the parents. RESULTS: We identified a novel homozygous deletion (c.549del; p.(Leu184Serfs*5)) in TREM2. Our literature review reveals 16 TREM2 mutations causing early-onset dementia and bone lesions. CONCLUSION: These findings, alongside previous research, elucidate the clinical spectrum of TREM2-related diseases, aiding accurate diagnosis and patient care. This knowledge is vital for understanding TREM2-dependent DAM and its involvement in the pathogenesis of neurodevelopmental disorders which can help to develop targeted therapies and improve outcomes for TREM2-affected individuals.

Identification and analyses of exonic and copy number variants in spastic paraplegia.

Hereditary spastic paraplegias are a diverse group of degenerative disorders that are clinically categorized as isolated; with involvement of lower limb spasticity, or symptomatic, where spastic paraplegia is complicated by further neurological features. We sought to identify the underlying genetic causes of these disorders in the participating patients. Three consanguineous families with multiple affected members were identified by visiting special schools in the Punjab Province. DNA was extracted from blood samples of the participants. Exome sequencing was performed for selected patients from the three families, and the data were filtered to identify rare homozygous variants. ExomeDepth was used for the delineation of the copy number variants. All patients had varying degrees of intellectual disabilities, poor speech development, spasticity, a wide-based gait or an inability to walk and hypertonia. In family RDHR07, a homozygous deletion involving multiple exons and introns of SPG11 (NC000015.9:g.44894055_449028del) was found and correlated with the phenotype of the patients who had spasticity and other complex movement disorders, but not those who exhibited ataxic or indeterminate symptoms as well. In families ANMD03 and RDFA06, a nonsense variant, c.985C > T;(p.Arg329Ter) in DDHD2 and a frameshift insertion‒deletion variant of AP4B1, c.965-967delACTinsC;p.(Tyr322SerfsTer14), were identified which were homozygous in the patients while the obligate carriers in the respective pedigrees were heterozygous. All variants were ultra-rare with none, or very few carriers identified in the public databases. The three loss of function variants are likely to cause nonsense-mediated decay of the respective transcripts. Our research adds to the genetic variability associated with the SPG11 and AP4B1 variants and emphasizes the genetic heterogeneity of hereditary spastic paraplegia.

Clinical and genetic characteristics of disorders of sex development in Sudanese patients

Given the scarce data on DSD in Sudan, we aimed to characterize DSD's clinical and genetic profile in Sudanese patients. We studied 60 patients with DSD using clinical data, cytogenetics, and PCR for the SRY gene. The results showed that 65% grew up as females and 35% as males. There was a high percentage of consanguineous parents (85%). Female genital mutilation (FGM) was performed in 75% of females. Patients who presented after pubertal age were 63%, with ambiguous genitalia in 61.7%, followed by primary amenorrhea (PA) in 30%. The SRY gene was positive in 3.3% of patients with 46,XX karyotype and negative in 6.7% of patients with 46,XY karyotype. 5αR2D-DSD was seen in 43.3%, gonadal dysgenesis in 21.7%, Ovotesticular syndrome in 6.7%, Swyer and Turner syndrome in 5% each, and Androgen Insensitivity Syndrome (AIS) in 3.3%. In conclusion, DSD in Sudan has a distinct profile with late presentation, dominated by 5αR2D-DSD due to the increased consanguineous marriage, and FGM represents a significant risk for DSD patients.

Compte tenu du peu de données sur le DSD au Soudan, nous avons cherché à caractériser le profil clinique et génétique du DSD chez les patients soudanais. Nous avons étudié 60 patients atteints de DSD en utilisant des données cliniques, cytogénétiques et PCR pour le gène SRY. Les résultats ont montré que 65 % ont grandi en tant que femmes et 35 % en tant qu'hommes. Il y avait un pourcentage élevé de parents consanguins (85 %). Des mutilations génitales féminines (MGF) ont été pratiquées chez 75 % des femmes. Les patientes qui se sont présentées après l'âge pubertaire étaient 63 %, avec des organes génitaux ambigus dans 61,7 %, suivis d'une aménorrhée primaire (AP) dans 30 %. Le gène SRY était positif chez 3,3 % des patients de caryotype 46,XX et négatif chez 6,7 % des patients de caryotype 46,XY. Le 5αR2D-DSD a été observé dans 43,3 %, la dysgénésie gonadique dans 21,7 %, le syndrome ovotesticulaire dans 6,7 %, le syndrome de Swyer et Turner dans 5 % chacun et le syndrome d'insensibilité aux androgènes (AIS) dans 3,3 %. En conclusion, le DSD au Soudan présente un profil distinct avec une présentation tardive, dominé par le 5αR2D-DSD en raison de l'augmentation des mariages consanguins, et les MGF représentent un risque important pour les patients DSD.

Distinct neurological phenotypes associated with biallelic loss of NOTCH3 function: evidence for recessive inheritance.

BACKGROUND: NOTCH3 variants are known to be linked to cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). However, some null NOTCH3 variants with homozygous inheritance cause neurological symptoms distinct from CADASIL. The aim of this study was to expand the clinical spectrum of this distinct condition and provide further evidence of its autosomal recessive inheritance. METHODS AND RESULTS: Whole exome sequencing (WES) was performed on a proband who exhibited livedo racemosa, ataxia, cognitive decline, seizures, and MRI white matter abnormalities without anterior temporal pole lesions. Segregation analysis was conducted with Sanger sequencing. WES of the proband identified a novel homozygous NOTCH3 null variant (c.2984delC). The consanguineous parents were confirmed as heterozygous variant carriers. In addition, three heterozygous NOTCH3 null variants were reported as incidental findings in three unrelated cases analyzed in our center. CONCLUSION: The findings of this study suggest an autosomal recessive inheritance pattern in this early-onset leukoencephalopathy, in contrast to CADASIL's dominant gain-of-function mechanism; which is a clear example of genotype-phenotype correlation. Comprehensive genetic analysis provides valuable insights into disease mechanisms and facilitates diagnosis and family planning for NOTCH3-associated neurological disorders.

The perception of genetic diseases and premarital screening tests in the central region of Saudi Arabia.

The prevalence of consanguineous marriages (CMs) varies worldwide from one country to another. However, the Middle East stands out as a region with a notably high rate of CMs. CM is particularly widespread in Saudi Arabia, where the prevalence of autosomal recessive genetic diseases has increased. This study aims to identify the Saudi population's awareness of genetic diseases and premarital screening tests (PMSTs). It also seeks to understand couples' perceptions of genetic diseases before and after marriage and their attitudes towards PMSTs and genetic counselling (GC) in reducing the risk of CM. Through the administration of online questionnaires, this cross-sectional study surveyed 2,057 participants to assess their awareness of genetic diseases and their understanding of testing and preventive measures for inherited diseases. Descriptive analysis, nonparametric chi-square tests and logistic regressions were performed to assess the association of categorical responses. This study included 2,035 Saudi Arabian respondents. A significant correlation was found between positive family history and partner selection (p = 0.001), as well as between partnering within the same tribe (p = 0.000139), with a different tribe (p = 0.000138) and from another family (p = 0.000489). About 91.3% of participants expressed agreement regarding the need to enhance public awareness and knowledge concerning genetic disorders, while 87% agreed that increased government regulations are required to prevent the spread of genetic diseases in affected families. Despite increased awareness of genetic diseases and PMSTs, there appears to be a lack of understanding regarding the limitations of PMSTs. The persistently high rate of CM underscores the challenge of altering marriage customs. Further governmental efforts are required to promote awareness of alternative reproductive options, establish new regulations and expand screening programmes.

Drawing human pedigree charts with DrawPed.

Creating pedigree charts is a recurring task in biomedical research, but there are few online tools for drawing complex human pedigrees available and even fewer are free. With DrawPed we aim to close this gap. DrawPed automatically draws pedigree charts from standard PED format pedigree files. Users can also create pedigrees from scratch and interactively edit existing pedigrees. The application can display conditions not captured in a PED file such as deceased persons or suspected consanguinity of parents. Pedigree charts are displayed as SVGs, which are scalable and hence publication-ready. Pedigrees can be exported as PED files for storage, exchange, or use in other applications. DrawPed is open source and freely available at https://www.genecascade.org/DrawPed/.

Next-generation sequencing to genetically diagnose a diverse range of inherited eye disorders in 15 consanguineous families from Pakistan.

Inherited retinal dystrophies (IRDs) are characterized by photoreceptor dysfunction or degeneration. Clinical and phenotypic overlap between IRDs makes the genetic diagnosis very challenging and comprehensive genomic approaches for accurate diagnosis are frequently required. While there are previous studies on IRDs in Pakistan, causative genes and variants are still unknown for a significant portion of patients. Therefore, there is a need to expand the knowledge of the genetic spectrum of IRDs in Pakistan. Here, we recruited 52 affected and 53 normal individuals from 15 consanguineous Pakistani families presenting non-syndromic and syndromic forms of IRDs. We employed single molecule Molecular Inversion Probes (smMIPs) based panel sequencing and whole genome sequencing to identify the probable disease-causing variants in these families. Using this approach, we obtained a 93% genetic solve rate and identified 16 (likely) causative variants in 14 families, of which seven novel variants were identified in ATOH7, COL18A1, MERTK, NDP, PROM1, PRPF8 and USH2A while nine recurrent variants were identified in CNGA3, CNGB1, HGSNAT, NMNAT1, SIX6 and TULP1. The novel MERTK variant and one recurrent TULP1 variant explained the intra-familial locus heterogeneity in one of the screened families while two recurrent CNGA3 variants explained compound heterozygosity in another family. The identification of variants in known disease-associated genes emphasizes the utilization of time and cost-effective screening approaches for rapid diagnosis. The timely genetic diagnosis will not only identify any associated systemic issues in case of syndromic IRDs, but will also aid in the acceleration of personalized medicine for patients affected with IRDs.

Consanguinty and its impact on health and genome dynamic: An example from Tunisia.

The genetic disease spectrum in Tunisia arises from the founder effect, genetic drift, selection, and consanguinity. The latter represents a deviation from panmixia, characterized by a non-random matrimonial choice that may be subject to several rules, such as socio-cultural, economic, or other factors. This shifts the genetic structure away from the Hardy-Weinberg equilibrium, increasing homozygous genotypes and decreasing heterozygotes, thus raising the frequency of autosomal recessive diseases. Similar to other Arab populations, Tunisia displays high consanguinity rates that vary geographically. Approximately 60% of reported diseases in Tunisia are autosomal recessive, with consanguinity possibly occurring in 80% of families for a specific disease. In inbred populations, consanguinity amplifies autosomal recessive disease risk, yet it does not influence autosomal dominant disease likelihood but rather impacts its phenotype. Consanguinity is also suggested to be a major factor in the homozygosity of deleterious variants leading to comorbid expression. At the genome level, inbred individuals inherit homozygous mutations and adjacent genomic regions known as runs of homozygosity (ROHs). Short ROHs indicate distant inbreeding, while long ROHs refer to recent inbreeding. ROHs are distributed rather irregularly across the genome, with certain short regions featuring an excess of ROH, known as ROH islands. In this review, we discuss consanguinity's impact on population health and genome dynamics, using Tunisia as a model.

Clinical genomics expands the link between erroneous cell division, primary microcephaly and intellectual disability.

Primary microcephaly is a rare neurogenic and genetically heterogeneous disorder characterized by significant brain size reduction that results in numerous neurodevelopmental disorders (NDD) problems, including mild to severe intellectual disability (ID), global developmental delay (GDD), seizures and other congenital malformations. This disorder can arise from a mutation in genes involved in various biological pathways, including those within the brain. We characterized a recessive neurological disorder observed in nine young adults from five independent consanguineous Pakistani families. The disorder is characterized by microcephaly, ID, developmental delay (DD), early-onset epilepsy, recurrent infection, hearing loss, growth retardation, skeletal and limb defects. Through exome sequencing, we identified novel homozygous variants in five genes that were previously associated with brain diseases, namely CENPJ (NM_018451.5: c.1856A > G; p.Lys619Arg), STIL (NM_001048166.1: c.1235C > A; p.(Pro412Gln), CDK5RAP2 (NM_018249.6 c.3935 T > G; p.Leu1312Trp), RBBP8 (NM_203291.2 c.1843C > T; p.Gln615*) and CEP135 (NM_025009.5 c.1469A > G; p.Glu490Gly). These variants were validated by Sanger sequencing across all family members, and in silico structural analysis. Protein 3D homology modeling of wild-type and mutated proteins revealed substantial changes in the structure, suggesting a potential impact on function. Importantly, all identified genes play crucial roles in maintaining genomic integrity during cell division, with CENPJ, STIL, CDK5RAP2, and CEP135 being involved in centrosomal function. Collectively, our findings underscore the link between erroneous cell division, particularly centrosomal function, primary microcephaly and ID.

A Retrospective Study of the Presentation, Diagnosis, Management, and Outcomes of 27 Patients with Osteogenesis Imperfecta at a Single Center in Türkiye.

BACKGROUND This retrospective study aimed to evaluate the presentation, diagnosis, management, and outcomes of 27 patients diagnosed with osteogenesis imperfecta at a single center in Türkiye between January 2011 and January 2020. MATERIAL AND METHODS We analyzed data from the medical records of 27 patients with osteogenesis imperfecta admitted to Çukurova University Faculty of Medicine, Department of Orthopedics and Traumatology, between January 2011 and January 2020. The data included the clinical examination notes of the cases classified according to the Sillence and Shapiro systems, age, sex, parental consanguinity, genetic analysis (DNA isolation) results, the number and localization of past fractures, treatment methods, complications, hypermobility, and ambulation scoring. RESULTS The mean age of the patients (n=13 male, n=14 female) was 10.4±7.4 years, ranging from 3 to 39 years. Almost half (n=15, 55.6%) had consanguineous parents. The patients had 131 fractures during the 9 years between January 2011 and January 2020, with the femur being the most commonly fractured bone; 13 patients (48.15%) received surgical and conservative treatments, while the remaining 14 underwent only conservative treatments. The results revealed a strong association between the number of fractures and the types of genetic mutations (P=0.004). CONCLUSIONS Study findings indicate that the type of genetic mutation was not significantly correlated with the risk of treatment complications in osteogenesis imperfecta cases. Nevertheless, the study reveals a noteworthy association between the type of mutation and the number of surgeries required. Specifically, patients with the COL1A1 mutation needed more surgeries.

Severe manifestation of Rauch-Azzarello syndrome associated with biallelic deletion of CTNND2.

CTNND2 encodes δ-catenin, a component of an adherens junction complex, and plays an important role in neuronal structure and function. To date, only heterozygous loss-of-function CTNND2 variants have been associated with mild neurodevelopmental delay and behavioral anomalies, a condition, which we named Rauch-Azzarello syndrome. Here, we report three siblings of a consanguineous family of Syrian descent with a homozygous deletion encompassing the last 19 exons of CTNND2 predicted to disrupt the transcript. All presented with severe neurodevelopmental delay with absent speech, profound motor delay, stereotypic behavior, microcephaly, short stature, muscular hypotonia with lower limb hypertonia, and variable eye anomalies. The parents and the fourth sibling were heterozygous carriers of the deletion and exhibited mild neurodevelopmental impairment resembling that of the previously described heterozygous individuals. The present study unveils a severe manifestation of CTNND2-associated Rauch-Azzarello syndrome attributed to biallelic loss-of-function aberrations, clinically distinct from the already described mild presentation of heterozygous individuals. Furthermore, we demonstrate novel clinical features in homozygous individuals that have not been reported in heterozygous cases to date.

Genetic backgrounds and clinical characteristics of congenital neutropenias in Israel.

BACKGROUND: Congenital neutropenias are characterized by severe infections and a high risk of myeloid transformation; the causative genes vary across ethnicities. The Israeli population is characterized by an ethnically diverse population with a high rate of consanguinity. OBJECTIVE: To evaluate the clinical and genetic spectrum of congenital neutropenias in Israel. METHODS: We included individuals with congenital neutropenias listed in the Israeli Inherited Bone Marrow Failure Registry. Sanger sequencing was performed for ELANE or G6PC3, and patients with wild-type ELANE/G6PC3 were referred for next-generation sequencing. RESULTS: Sixty-five patients with neutropenia were included. Of 51 patients with severe congenital neutropenia, 34 were genetically diagnosed, most commonly with variants in ELANE (15 patients). Nine patients had biallelic variants in G6PC3, all of consanguineous Muslim Arab origin. Other genes involved were SRP54, JAGN1, TAZ, and SLC37A4. Seven patients had cyclic neutropenia, all with pathogenic variants in ELANE, and seven had Shwachman-Diamond syndrome caused by biallelic SBDS variants. Eight patients (12%) developed myeloid transformation, including six patients with an unknown underlying genetic cause. Nineteen (29%) patients underwent hematopoietic stem cell transplantation, mostly due to insufficient response to treatment with granulocyte-colony stimulating factor or due to myeloid transformation. CONCLUSIONS: The genetic spectrum of congenital neutropenias in Israel is characterized by a high prevalence of G6PC3 variants and an absence of HAX1 mutations. Similar to other registries, for 26% of the patients, a molecular diagnosis was not achieved. However, myeloid transformation was common in this group, emphasizing the need for close follow-up.