Some ectodermal dysplasias are here classified as congenital disorders characterized by abnormal development in 2 or more ectodermal structures (hair, nails, teeth, and sweat glands) without other systemic findings. Ectodermal dysplasia-8 is an autosomal recessive disorder characterized by abnormal development of hair, teeth, and nails.

Hypotrichosis-11 (HYPT11) is a form of isolated alopecia characterized by diffuse and progressive loss of hair starting in childhood. Affected individuals typically present with sparse to absent scalp hair, and may have brittle or absent eyebrows and eyelashes as well as sparse body hair, without hair shaft anomalies (summary by Pan et al., 2021). For a general phenotypic description and a discussion of genetic heterogeneity of nonsyndromic hypotrichosis, see HYPT1 (605389).

Any hypotrichosis in which the cause of the disease is a mutation in the RPL21 gene.