Previously undescribed nonsense mutation in SHH caused autosomal dominant holoprosencephaly with wide intrafamilial
Monica Marini1, Roberto Cusano, Pierangela De Biasio
1Laboratorio di Genetica Molecolare, Istituto G Gaslini, Genova, Italy.
Abstract:
Holoprosencephaly (HPE) is the most common developmental defect of the forebrain and midface in humans, with a frequency of 1/16,000 live births. Different genes are implicated in the pathogenesis of HPE; these include SHH, ZIC2, SIX3, TGIF, and human DKK1. We describe here a family with recurrence of autosomal dominant HPE in different members showing a wide clinical variability. The mother presents a single central maxillary incisor and mild hypotelorism as signs of the diseases, while three of her sons were affected by HPE. By direct sequencing and restriction analysis of exon 2 of the SHH gene, we have identified a previously undescribed nonsense mutation at codon 128 (W128X). The identification of this mutation allowed us to give a prenatal diagnosis in this family and confirms a wide intrafamilial variability in the phenotypic spectrum.
Related Concept Videos
Pleiotropy
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Neurulation
Genomic Imprinting and Inheritance
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
Alternative RNA Splicing
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
Huntington Disease l: Introduction


