Duplications in the~2 Mb desert region upstream of SOX9 at 17q24.3 may result in familial 46,XX disorders of sex development (DSD) without any effects on the XY background. A balanced translocation with its breakpoint falling within the same region has also been described in one XX DSD subject. We analyzed, by conventional and molecular cytogenetics, 19 novel SRY-negative unrelated 46,XX subjects both familial and sporadic, with isolated DSD. One of them had a de novo reciprocal t(11;17) translocation. Two cases carried partially overlapping 17q24.3 duplications~500 kb upstream of SOX9, both inherited from their normal fathers. Breakpoints cloning showed that both duplications were in tandem, whereas the 17q in the reciprocal translocation was broken at~800 kb upstream of SOX9, which is not only close to a previously described 46,XX DSD translocation, but also to translocations without any effects on the gonadal development. A further XX male, ascertained because of intellectual disability, carried a de novo cryptic duplication at Xq27.1, involving SOX3. CNVs involving SOX3 or its flanking regions have been reported in four XX DSD subjects. Collectively in our cohort of 19 novel cases of SRY-negative 46,XX DSD, the duplications upstream of SOX9 account for~10.5% of the cases, and are responsible for the disease phenotype, even when inherited from a normal father. Translocations interrupting this region may also affect the gonadal development, possibly depending on the chromatin context of the recipient chromosome. SOX3 duplications may substitute SRY in some XX subjects. European Journal of Human Genetics (2015) 23, 1025-1032; doi:10.1038/ejhg.2014.237; published online 5 November 2014 INTRODUCTION 46,XX disorders of sex development (DSDs) are congenital conditions in which, in the presence of a female karyotype, the development of gonadal and anatomical sex is atypical, ranging from various degrees of ambiguous genitalia to phenotypic males with azoospermia. These conditions are poorly characterized, at least in subjects whose DNA does not contain SRY, the gene triggering testis differentiation in mammals. 1 In fact, in most XX males, SRY is transposed to the tip of Xp as a consequence of a recurrent Xp;Yp translocation, arising predominantly by nonallelic homologous recombination between PRKX and PRKY on a particular Y haplotypic background. 2,3 These males, usually with small testes, are essentially picked up among men with nonobstructive azoospermia.A much less well-understood category is that of the 46,XX DSDs negative for SRY. Recently, six of these cases have been reported

Recently, germline mutations of NRAS have been shown to be associated with Noonan syndrome (NS), a relatively common developmental disorder characterized by short stature, congenital heart disease, and distinctive facial features. We report on the mutational analysis of NRAS in a cohort of 125 French patients with NS and no known mutation for PTPN11, KRAS, SOS1, MEK1, MEK2, RAF1, BRAF, and SHOC2. The c.179G>A (p.G60E) mutation was identified in two patients with typical NS, confirming that NRAS germline mutations are a rare cause of this syndrome. We also screened our cohort of 95 patients with juvenile myelomonocytic leukemia (JMML). Among 17 patients with NRAS-mutated JMML, none had clinical features suggestive of NS. None of the 11 JMML patients for which germline DNA was available had a constitutional NRAS mutation.

Steroid 11β-hydroxylase deficiency is the second most common cause of congenital adrenal hyperplasia, resulting in virilization, glucocorticoid deficiency and hypertension. The 11β-hydroxylase enzyme is encoded by the CYP11B1 gene and mutations in this gene are responsible for this disease. The aim of this study was to characterize mutations in the CYP11B1 gene and to determine their frequencies in a cohort of Tunisian patients. The molecular genetic analysis was performed by direct nucleotide sequencing of the CYP11B1 gene in 15 unrelated Tunisian patients suffering from classical 11β-hydroxylase deficiency. Only two mutations were detected in homozygous state in the CYP11B1 gene of all patients, the p.Q356X in exon 6 (26.6%) and the novel p.G379V in exon 7 with large prevalence (73.3%). This is the first report of screening for mutations of CYP11B1 gene in the Tunisian population and even in the Arab population.

Juvenile myoclonic epilepsy (JME) is characterized by seizures, severe cognitive abnormalities, and behavior impairments. These features could evolve over time and get worse, especially when the encephalopathy is pharmacoresistant. Thus, genetic studies should provide a better understanding of infantile epilepsy syndromes. Herein, we investigate the genetics of JME in a consanguineous family analyzing the copy number variations detected using over 700 K SNP arrays. We identified a 254-kb deletion in the 22q11.2 region, including only the TOP3B gene, detected in the patient and her father. TOP3B encodes a topoisomerase DNA (III) β protein and has been implicated in several neurological diseases such as schizophrenia and autism. In this study, we discuss the implication of the 22q11.2 region in neurodevelopmental disorders and the association of TOP3B with epilepsy.

No abstract

Pediatric cardiomyopathy is a complex disease with clinical and genetic heterogeneity. Recently, the ALPK3 gene was described as a new hereditary cardiomyopathy gene underlying pediatric cardiomyopathies. Only eight patients carrying mutations in ALPK3 have been reported to date. Here, we report a 3-year-old male patient with both hypertrophic and dilated cardiomyopathy. The patient presented dysmorphic features and skeletal deformities of hands and feet, pectus excavatum, and cleft palate. The genetic investigation was performed by whole-exome sequencing in the patient and his parents. We identified a novel homozygous mutation in ALPK3 (c.1531_1532delAA; p.Lys511Argfs*12). Our work extends the phenotypic spectrum of the ALPK3-associated cardiomyopathy by reporting additional clinical features. This is the first study of a Tunisian patient with mutation in the ALPK3 gene. In conclusion, ALPK3 should be included in the list of genes to be considered in genetic studies for patients affected with pediatric syndromic cardiomyopathy.

No abstract

Background: Noonan Syndrome (NS) is a relatively common autosomal dominant condition, caused by germline mutations in different genes involved in the RAS MAP Kinase signaling pathway. Although clinically heterogeneous, characteristic findings include typical facial features, short stature, chest deformity and congenital heart diseases.