Congenital Neuronal Ceroid Lipofuscinosis with a Novel CTSD Gene Mutation: A Rare Cause of Neonatal-Onset Neurodegenerative Disorder.

Neuronal ceroid lipofuscinoses represent a heterogeneous group of early onset neurodegenerative disorders that are characterized by progressive cognitive and motor function decline, visual loss, and epilepsy. The age of onset has been historically used for the phenotypic classification of this group of disorders, but their molecular genetic delineation has now enabled a better characterization, demonstrating significant genetic heterogeneity even among individuals with a similar phenotype. The rare Congenital Neuronal Ceroid Lipofuscinosis (CLN10) caused by mutations in the CTSD gene encoding for cathepsin D is associated with a dramatic presentation with onset before or around birth. We report on a female born to consanguineous parents who presented at birth with severe neonatal encephalopathy with massive cerebral and cerebellar shrinking on magnetic resonance imaging. Whole exome sequencing with targeted bioinformatic analysis of a panel of genes associated with prenatal/perinatal onset of neurodegenerative disease was performed and revealed the presence of a novel homozygous in-frame deletion in CTSD. Additional functional studies further confirmed the pathogenic character of this variant and established the diagnosis of CLN10 in the patient.

Experience of a multidisciplinary task force with exome sequencing for Mendelian disorders.

BACKGROUND: In order to optimally integrate the use of high-throughput sequencing (HTS) as a tool in clinical diagnostics of likely monogenic disorders, we have created a multidisciplinary "Genome Clinic Task Force" at the University Hospitals of Geneva, which is composed of clinical and molecular geneticists, bioinformaticians, technicians, bioethicists, and a coordinator. METHODS AND RESULTS: We have implemented whole exome sequencing (WES) with subsequent targeted bioinformatics analysis of gene lists for specific disorders. Clinical cases of heterogeneous Mendelian disorders that could potentially benefit from HTS are presented and discussed during the sessions of the task force. Debate concerning the interpretation of identified variants and the content of the final report constitutes a major part of the task force's work. Furthermore, issues related to bioethics, genetic counseling, quality control, and reimbursement are also addressed. CONCLUSIONS: This multidisciplinary task force has enabled us to create a platform for regular exchanges between all involved experts in order to deal with the multiple complex issues related to HTS in clinical practice and to continuously improve the diagnostic use of HTS. In addition, this task force was instrumental to formally approve the reimbursement of HTS for molecular diagnosis of Mendelian disorders in Switzerland.

Multiplex targeted high-throughput sequencing for Mendelian cardiac disorders.

Mendelian cardiomyopathies and arrhythmias are characterized by an important genetic heterogeneity, rendering Sanger sequencing very laborious and expensive. As a proof of concept, we explored multiplex targeted high-throughput sequencing (HTS) as a fast and cost-efficient diagnostic method for individuals suffering from Mendelian cardiac disorders. We designed a DNA capture assay including all exons from 130 genes involved in cardiovascular Mendelian disorders and analysed simultaneously four samples by multiplexing. Two patients had familial hypertrophic cardiomyopathy (HCM) and two patients suffered from long QT syndrome (LQTS). In patient 1 with HCM, we identified two known pathogenic missense variants in the two most frequently mutated sarcomeric genes MYH7 and MYBPC. In patient 2 with HCM, a known acceptor splice site variant in MYBPC3 was found. In patient 3 with LQTS, two missense variants in the genes SCN5A and KCNQ were identified. Finally, in patient 4 with LQTS a known missense variant was found in MYBPC3, which is usually mutated in patients with cardiomyopathy. Our results showed that multiplex targeted HTS works as an efficient and cost-effective tool for molecular diagnosis of heterogeneous disorders in clinical practice and offers new insights in the pathogenesis of these complex diseases.

[Pregnancy and Ehlers-Danlos vascular syndrome: patients' care and complications]. / Grossesse et syndrome d'Ehlers-Danlos vasculaire : prise en charge et complications.

INTRODUCTION: Elhers-Danlos vascular syndrome type IV (EDS4) is a hereditary pathology of the connective tissue responsible for an increased risk of lethal arterial, uterine and digestive complications during and after pregnancy. PATIENTS AND METHODS: We describe the obstetrical care, the nature and frequency of complications related to pregnancy of patients with EDS4 and their relatives. RESULTS: Twenty-seven pregnancies were studied including 23 deliveries, 18 vaginal deliveries and five caesarean, no maternal death and two major life-threatening complications (8.7%) were recorded which could be directly linked to EDS4 (rupture of the biscupid valve pillar after vaginal delivery and a rupture of the caecum after a prophylactic caesarean). Ten deliveries underwent epidural anesthesia without complication. Six perineal injuries (33.3%) were observed. CONCLUSION: Pregnancy in patient with EDS4 needs obstetrical cares in a special unit's motivated medical team with intensive care and surgical disponibilities.

[The contribution of molecular genetics to clinical cardiology: the example of hypertrophic cardiomyopathy]. / L'apport de la génétique moléculaire en cardiologie clinique: l'exempte de la cardiomyopathie hypertrophique.

Recent advances in molecular genetics have resulted in the identification of pathogenic mutations in a number of genes which cause hypertrophic cardiomyopathy (HCM). In order to integrate this increasing genetic knowledge of HCM into the cardiology clinic, we offer all patients and their families diagnosis and genetic counselling based on these current data. In addition, within the framework of a multidisciplinary project between the Divisions of Medical Genetics, Cardiology and Pediatric Cardiology of the University Hospitals of Geneva, we have developed a resequencing array enabling rapid molecular diagnosis of HCM. Data from this study will enhance our understanding of the aetiology of HCM, and improve our knowledge of genotype-phenotype correlations. This information will enable us to develop new therapeutic and preventive concepts, with the aim of tailoring therapies to the specific genetic variant of each patient and its family.

Velofacial hypoplasia (Sedlackova syndrome): a variant of velocardiofacial (Shprintzen) syndrome and part of the phenotypical spectrum of del 22q11.2.

UNLABELLED: In 1955, a pattern of velar hypoplasia causing hypernasal speech and associated facial dysmorphism was observed in 26 children of Czech origin. Further cases with submucous cleft and/or cardiac anomalies were described. In 1978 velocardiofacial syndrome (VCFS) was reported, a condition very similar to velofacial hypoplasia (Sedlackova syndrome) apart from overt clefts instead of velar hypoplasia. In 1990 it was suggested that both syndromes might be variants of the same clinical entity. To test this hypothesis we performed fluorescence in situ hybridisation using the DiGeorge/VCFS region specific probe D22S75 on 20 patients originally classified as Sedlackova syndrome as well as molecular investigations for a subset of these patients. A 22q11.2 deletion was found in 16/20 patients. Thus, our results confirm the aforementioned hypothesis and expand the long list of clinical diagnoses associated with del 22q11.2. CONCLUSION: Velofacial hypoplasia (Sedlackova syndrome) and velocardiofacial (Shprintzen) syndrome have a corresponding phenotype and are both associated with del 22q11.2.

The contribution of uniparental disomy to congenital development defects in children born to mothers at advanced childbearing age.

Most instances of maternal uniparental disomy (UPD) start as trisomies and, similar to the latter, show a significant increase of mean maternal age at delivery. To investigate the incidence of UPD in offspring of older mothers, we investigated two groups of patients: 1) 50 patients with unclassified developmental defects born to mothers 35 years or older at delivery were tested for UPD for all autosomes by means of microsatellite marker analysis; 2) The incidence of UPD versus other etiologies in correlation, with maternal age below versus 35 years and above at delivery was studied in patients investigated in our laboratory for maternal UPD 15 (Prader-Willi syndrome, PWS), paternal UPD 15 (Angelman syndrome, AS), and maternal UPD 7 (Silver-Russell syndrome, SRS). In group 1, four patients of 50 showed UPD for an autosome that clarified the etiology of their developmental problems: a 27-year-old woman with growth retardation and early puberty disclosed maternal heterodisomy 14; a 15-year-old girl revealed paternal isodisomy 15; a 6-year-old boy with suspected Smith-Lemli-Opitz syndrome was shown to have maternal heterodisomy 16 with additional mosaic partial trisomy 16(pter-p13); a 16-month-old girl with intrauterine growth retardation and a dysmorphic pattern revealed maternal heterodisomy 7. In group 2 the offspring of older mothers showed a clear increase of UPD compared with the mothers below 35 years at delivery. The binomial distribution gave P-values of 1.9 x 10(-10), 2.6 x 10(-4), and 0.01 for PWS, AS, and SRS, respectively. The correlation between increase of paternal UPD 15 with advanced maternal age might be explained by maternal non-disjunction leading to hypohaploid gamete (nullisomy) for chromosome 15 with subsequent or concomitant duplication of the paternal homologue (paternal isodisomy). The three UPD 15 AS cases with mothers older than 35 years at delivery revealed isodisomy, whereas the three cases from younger mothers showed heterodisomy. This study confirms the hypothesis that uniparental disomy is a not negligible cause of congenital developmental anomalies in children of older mothers.

Maternal uniparental disomy 14 as a cause of intrauterine growth retardation and early onset of puberty.

Uniparental disomy for particular chromosomes is increasingly recognized as a cause of abnormal phenotypes in humans either as a result of imprinted genes or, in the case of isodisomy, homozygosity of mutated recessive alleles. We report on the occurrence of maternal uniparental disomy for chromosome 14 (matUPD 14) in a 25-year-old woman with a normal karyotype, normal intelligence but low birth weight, short stature, small hands, and early onset of puberty. Comparison of her phenotype with those of 15 previously described liveborn patients with matUPD14 gives further evidence for an imprinted gene region on chromosome 14 and highlights the necessity to consider this cause in children with intrauterine growth retardation and early onset of puberty caused by acceleration of skeletal maturation.

22q11.2 deletions in a series of patients with non-selective congenital heart defects: incidence, type of defects and parental origin.

Previous studies have indicated a wide spectrum of incidences of 22q11.2 deletions in isolated and syndromic (sporadic or familial) cases of conotruncal heart defects, whereby the detection rate of the deletion varied from 65% in one study to 0 in another. We analysed 110 patients with non-selective syndromic or isolated non-familial congenital heart malformations by fluorescence in situ hybridization (FISH) using the D22S75 DiGeorge chromosome (DGS) region probe. A 22q11.2 microdeletion has been detected in 9/51 (17.6%) syndromic patients. Five were of maternal origin and four of paternal origin. None of the 59 patients with isolated congenital cardiac defect had a 22q11.2 deletion. We compared the cardiac anomalies of our patients with a 22q11.2 deletion with those of previously published series and we describe types of congenital heart defects which appear to be often associated with a 22q11.2 deletion. The ability to detect such types of heart defects and to provide an early diagnosis of 22q11.2 deletion is particularly relevant in very young infants, who often show only very mild expression of the otherwise well-characterized phenotypes of the DiGeorge/velo-cardio-facial syndrome (DG/VCFS).

Laryngeal atresia type III (glottic web) with 22q11.2 microdeletion: report of three patients.

The clinical manifestations of patients with a 22q11.2 deletion are highly variable and mainly include developmental defects of structures derived from the third and fourth pharyngeal pouches. Laryngeal atresia has occasionally been reported in DiGeorge syndrome as well as in velo-cardio-facial syndrome. We observed three patients with type III laryngeal atresia (glottic web) and 22q11.2 microdeletion. One patient showed a "classical" 22q11.2 deletion phenotype with clinical overlap with DiGeorge and velo-cardio-facial syndromes. However, the pattern of congenital anomalies of the two others was less specific, heart defects and minor anomalies being the only outstanding clinical manifestations suspicious for monosomy 22q11.2. Our findings suggest that laryngeal atresia represents an additional malformation which should prompt investigation of 22q11.2 deletion, especially in combination with congenital heart defects.