Heterozygous KRT32 Variant Is Responsible for Autosomal Dominant Loose Anagen Hair Syndrome

May 2025

Manuela A. Melo, Elizabeth Phillippi, Thomas O. Moninger, Kya Foxx, Benjamin W. Darbro, Kelly N. Messingham, Edward A. Sander, Hatem El‐Shanti

KRT32 loose anagen hair syndrome non-scarring alopecia KRT82 intermediate filament anagen hair

Studysummary In this study, researchers identified the c.296C>T (p.T99I) variant in the KRT32 gene, which co-segregates with loose anagen hair syndrome, and found it decreases binding affinity to KRT82, potentially weakening hair anchorage. Our plain-language summary of this paper — not a Tressless recommendation.

This study identifies a heterozygous c.296C>T (p.T99I) variant in the KRT32 gene as a likely cause of autosomal dominant loose anagen hair syndrome, a type of non-scarring alopecia. The research involved a large family with the condition and demonstrated that the p.T99I variant reduces the binding affinity of KRT32 to KRT82, disrupting the intermediate filament structure in the hair shaft cuticle. This disruption leads to weak anchorage of anagen hair. The findings were supported by protein-protein interaction assays and in silico analyses, showing significant differences in filament structure between the variant and wild-type groups.

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