Two new cases of interstitial 7q35q36.1 deletion including CNTNAP2 and KMT2C.

Background: Terminal deletions of the long arm of chromosome 7 are well known and frequently associated with syndromic holoprosencephaly due to the involvement of the SHH (aliases HHG1, SMMCI, TPT, TPTPS, and MCOPCB5) gene region. However, interstitial deletions including CNTNAP2 (aliases Caspr2, KIAA0868, and NRXN4) and excluding the SHH region are less common.

Methods: We report the clinical and molecular characterization associated with pure 7q35 and 7q35q36.

Loss of the KH1 domain of FMR1 in humans due to a synonymous variant causes global developmental retardation.

Background: Fragile X syndrome (FXS) is a monogenic disorder and a common cause of intellectual disability (ID). Up to now, very few pathological variants other than the typical CGG-repeat expansion have been reported in the FMR1 gene.

Methods: A panel of 56 intellectual disability (ID) genes including the FMR1 gene was sequenced in a cohort of 300 patients with unexplained ID.