Rare variants in the genetic background modulate cognitive and developmental phenotypes in individuals carrying disease-associated variants
Purpose: To assess the contribution of rare variants in the genetic background toward variability of neurodevelopmental phenotypes in individuals with rare copy-number variants (CNVs) and gene-disruptive variants. Methods: We analyzed quantitative clinical information, exome sequencing, and microarray data from 757 probands and 233 parents and siblings who carry disease-associated variants. Results: The number of rare likely deleterious variants in functionally intolerant genes (“other hits”) correlated with expression of neurodevelopmental phenotypes in probands with 16p12.1 deletion (n=23, p=0.004) and in autism probands carrying gene-disruptive variants (n=184, p=0.03) compared with thei…
Identification of novel mutations in L1CAM gene by a DHPLC-based assay
X-linked hydrocephalus, MASA syndrome, X-linked complicated Spastic Paraplegia Type I, and X-linked partial agenesis of the corpus callosum are rare diseases mainly affecting male population and broadly referred as L1 syndrome, caused by mutations in the L1CAM gene. In the present study 36 boys and a male fetus whose clinical features were consistent with L1 syndrome were analyzed by dHPLC assay and direct sequencing of L1CAM gene. Sequence analysis of the 14 different aberrant dHPLC elution profiles demonstrated that six of them were associated with already reported polymorphisms, four with previously described causative variants while the remaining four represented novel L1CAM mutations. …
Rare variants in the genetic background modulate the expressivity of neurodevelopmental disorders
AbstractPurposeTo assess the contribution of rare variants in the genetic background towards variability of neurodevelopmental phenotypes in individuals with rare copy-number variants (CNVs) and gene-disruptive mutations.MethodsWe analyzed quantitative clinical information, exome-sequencing, and microarray data from 757 probands and 233 parents and siblings who carry disease-associated mutations.ResultsThe number of rare secondary mutations in functionally intolerant genes (second-hits) correlated with the expressivity of neurodevelopmental phenotypes in probands with 16p12.1 deletion (n=23, p=0.004) and in probands with autism carrying gene-disruptive mutations (n=184, p=0.03) compared to …