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The c.940G variant of the Microcephalin (MCPH1) gene is not associated with microcephaly or mental retardation

Reycel Maghirang-Rodriguez1, John G Archie, Charles E Schwartz

  • 1JC Self Research Institute of Human Genetics, Greenwood Genetic Center, Greenwood, South Carolina 29646, USA.

American Journal of Medical Genetics. Part A
|March 10, 2009
PubMed

Insights

This study investigated the Microcephalin (MCPH1) gene

Area of Science:

  • Human Genetics
  • Neuroscience
  • Population Genetics

Background:

  • The Microcephalin (MCPH1) gene, located on chromosome 8p23, is implicated in autosomal recessive primary microcephaly.
  • Previous research suggested positive selection acting on the MCPH1 gene.

Purpose of the Study:

  • To determine if the MCPH1 c.940G > C single nucleotide polymorphism (SNP) is associated with microcephaly or mental retardation (MR).
  • To compare allele frequencies of the MCPH1 c.940G > C SNP in African-American and Caucasian populations with and without MR and microcephaly.

Main Methods:

  • Genotyping of the MCPH1 c.940G > C SNP in individuals with and without microcephaly and mental retardation.
  • Population-based analysis comparing allele frequencies between African-American and Caucasian cohorts in South Carolina.

Main Results:

  • No significant association was found between the MCPH1 c.940G allele and microcephaly or mental retardation.
  • Highly significant differences in MCPH1 c.940G > C SNP allele frequencies were observed between African-American and Caucasian populations.

Conclusions:

  • The MCPH1 c.940G allele is unlikely to be a major genetic factor contributing to microcephaly or mental retardation in the studied populations.
  • Significant population-specific allele frequency differences highlight the importance of considering race in genetic association studies of MCPH1.

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