OMIM®:
57
Hypotrichosis simplex can affect all body hair (generalized; see 605389) or be limited to the scalp. Usually patients with the scalp-limited form of hypotrichosis present with normal hair at birth; they experience a progressive, gradual loss of scalp hair beginning at the middle of the first decade and leading to almost complete loss of scalp hair by the third decade. A few sparse, fine, short hairs remain in some individuals. Body hair, beard, eyebrows, axillary hair, teeth, and nails develop normally. Light and electron microscopy of hairs from patients with early hypotrichosis simplex revealed no structural changes, whereas hairs from patients with advanced hypotrichosis showed focal areas of defective cuticular structure. Men and women are equally affected (summary by Betz et al., 2000).
For a discussion of genetic heterogeneity of nonsyndromic hypotrichosis, see HYPT1 (605389). (613981) (Updated 08-Dec-2022)
MalaCards based summary:
Hypotrichosis 3, also known as hypotrichosis simplex of the scalp 2, is related to hypotrichosis 1 and mucinoses. An important gene associated with Hypotrichosis 3 is KRT74 (Keratin 74), and among its related pathways/superpathways is RAB geranylgeranylation. Related phenotype is sparse scalp hair.
UniProtKB/Swiss-Prot:
73
A condition characterized by the presence of less than the normal amount of hair. Affected individuals have normal hair in early childhood but experience progressive hair loss limited to the scalp beginning in the middle of the first decade and almost complete baldness by the third decade. Body hair, beard, eyebrows, axillary hair, teeth, and nails develop normally. HYPT3 inheritance is autosomal dominant.
Disease Ontology:
11
A hypotrichosis that has material basis in a autosomal dominant mutation of KRT74 on chromosome 12q13.13.
