Related Experiment Video
Updated: Jul 6, 2026
Investigating the Pathogenesis of MYH7 Mutation Gly823Glu in Familial Hypertrophic Cardiomyopathy using a Mouse Model
Published on: August 8, 2022
New mutation, P575L, in the GUCY2D gene in a family with autosomal dominant progressive cone degeneration
Kent W Small1, Rosamaria Silva-Garcia, Nitin Udar
1Molecular Insight LLC, Los Angeles, CA 90049, USA. kentsmall@hotmail.com
Objectives:
To clinically characterize the retinal abnormalities and identify the mutation causing an autosomal dominant cone degeneration in an African American family.
Methods:
Clinical characterization of family members using fundus photography, fluorescein angiography, and electrophysiological testing. Standard molecular genetic methods were used, including segregation analysis and DNA sequencing of candidate genes. Genetic mutation screening was performed in 20 individuals: 10 clinically unaffected and 10 affected.
Results:
The affected family members had findings consistent with a primary cone degeneration. A novel mutation, P575L, was found in exon 8 of the GUCY2D gene in 12 members of this family.
Conclusions:
In addition to finding a previously undescribed mutation in GUCY2D, 2 of the family members who were thought to be unaffected through routine clinical examinations also had this mutation. These findings suggest that autosomal dominant cone degeneration in this family demonstrated age-dependent penetrance, which appears incomplete. This is the first African American family reported with a mutation in GUCY2D. Because the disease in this family and the one we previously described is primarily a cone degeneration, this disease should be more properly classified as cone degeneration and be called cone degeneration 2.
Clinical Relevance:
This study helps to expand the phenotype of the disease and help clinicians identify patients with cone degenerations.
Related Concept Videos
01:11Genetic Lingo
01:39Mutations
01:43Incomplete Dominance
02:41Lethal Alleles
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
01:21Huntington Disease l: Introduction
01:20The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...