Exome sequencing identifies three novel candidate genes implicated in intellectual disability

Area of Science:

• Genetics
• Neuroscience
• Molecular Biology

Background:

• Intellectual disability (ID) presents a significant global health challenge with largely unknown genetic underpinnings.
• Recent advancements in exome sequencing have begun to reveal novel genes associated with ID.

Purpose of the Study:

• To investigate the genetic etiology of intellectual disability in one syndromic and two non-syndromic Pakistani families.
• To identify novel genes implicated in both autosomal recessive and dominant forms of ID.

Main Methods:

• Whole exome sequencing was performed on three individuals with intellectual disability (ID).
• Analysis focused on identifying missense variations in candidate genes, including KMT2B, ZNF589, and HHAT.

Main Results:

• Identified missense variations in KMT2B and ZNF589, suggesting autosomal recessive ID.
• Discovered a de novo mutation in HHAT, indicating an autosomal dominant mode of inheritance.
• The KMT2B variant represents the first reported recessive Kleefstra syndrome-like phenotype.

Conclusions:

• The study underscores the extensive genetic heterogeneity of ID by identifying novel causative genes.
• Findings suggest convergence of ID-associated genes on common biological networks, including epigenetic regulation and signaling pathways.
• Recommends screening these novel genes in broader populations to confirm their role in ID pathogenesis.