Lanceolate Hair (Lah): A Recessive Mouse Mutation with Alopecia and Abnormal Hair
TLDR Mice with the 'lanceolate hair' mutation have abnormal hair and skin similar to human Netherton's syndrome.
The document reports on a newly identified autosomal recessive mutation in house mice, named 'lanceolate hair' (lah), which was induced by ethylnitrosourea in a mutagenesis experiment. Mice with this mutation exhibited generalized alopecia due to hair shaft breakage, with the hair shafts being short and showing a lance head-like enlargement at the breakpoint. The hair fibers measured between 2.0 to 3.5 mm and had a normal base, indicating a synchronized developmental defect. Histological analysis showed abnormal cornification in the matrix region of anagen follicles and pronounced dystrophy in catagen follicles, while telogen follicles appeared almost normal. Additionally, there was significant thickening of the epidermis and a non-scarring, relatively non-inflammatory ichthyosiform dermatitis. These symptoms are similar to those of Netherton's syndrome in humans, suggesting that the lah mutation could serve as a model for this condition. The mutation was localized to the centromeric end of mouse Chromosome 18.