Background: High resolution genome-wide copy number analysis, routinely used in clinical diagnosis for several years, retrieves new and extremely rare copy number variations (CNVs) that provide novel candidate genes contributing to disease etiology. The aim of this work was to identify novel genetic causes of neurodevelopmental disease, inferred from CNVs detected by array comparative hybridization (aCGH), in a cohort of 325 Portuguese patients with intellectual disability (ID). Results: We have detected CNVs in 30.1% of the patients, of which 5.2% corresponded to novel likely pathogenic CNVs. For these 11 rare CNVs (which encompass novel ID candidate genes), we identified those most likely to be relevant, and established genotype-phenotype correlations based on detailed clinical assessment. In the case of duplications, we performed expression analysis to assess the impact of the rearrangement. Interestingly, these novel candidate genes belong to known ID-related pathways. Within the 8% of patients with CNVs in known pathogenic loci, the majority had a clinical presentation fitting the phenotype(s) described in the literature, with a few interesting exceptions that are discussed. Conclusions: Identification of such rare CNVs (some of which reported for the first time in ID patients/families) contributes to our understanding of the etiology of ID and for the ever-improving diagnosis of this group of patients.
SummaryThe Kallmann syndrome is characterised by the association of hypogonadotropic hypogonadism and hypo/anosmia. It represents a phenotypically and genotypically heterogeneous clinical entity, with six genes identified so far in the literature-KAL1, FGFR1, PROKR2, PROK2, CHD7 and FGF8. Mutations in the FGFR1 gene can be found in approximately 10% of the patients. The authors present the case of a female adolescent with hypogonadotropic hypogonadism and impaired olfactory acuity in the presence of hypoplasia of the nasal sulcus and agenesis of the olfactory bulbs. The molecular analysis of the fibroblast growth factor receptor 1 identified a heterozygous mutation c.1377_78insA ( p.V460SfsX3) in exon 10 of FGFR1 gene. This mutation has not yet been reported in the literature. A theoretical review of clinical features and therapeutic approach of this syndrome is also presented.
BACKGROUND
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.