Molecular basis of a novel rhino (hrrhChr) phenotype: a nonsense mutation in the mouse hairless gene

The hairless and rhino mutations are autosomal recessive allelic mutations that map to mouse Chromosome 14. In general, the rhino phenotype is a more severe manifestation of the hairless phenotype. In both hairless and rhino mice, the hair begins shedding in a cephalocaudal pattern within 7 days after birth, and never regrows due to a series of irreversible cellular events. The hairless mutation closely resembles the human disease known as papular atrichia (MIM 209500). Recently, this disease was linked to Chromosome 8p12, the human homolog of hairless was cloned and mapped to the same locus, and mutations have been identified in several different families. In order to gain insight into the pathophysiology of disease in papular atrichia, we sought to utilize mouse mutations as in vivo model systems. In this study, we report the identification of a homozygous nonsense mutation in the coding region of the hr gene in a hairless mouse captured on a chicken farm in the Midwestern United States. To reflect the place of identification of this new mutation at the hr locus, we have designated this allele hrrhChr using the laboratory code Chr (Christiano).