woolly hair syndrome
A popular term for tight curly hair which is first seen at birth in some Caucasians and light-skinned African Americans. It may be:
(1) Sporadic woolly hair and associated with woolly hair nevus (OMIM:162900)
(2) Hypotrichosis 8 An autosomal recessive condition (OMIM:278150), in which the scalp hair is ash-white and the body hair is short and kinky.
Molecular pathology Hypotrichosis 8 is caused by defects in LPAR6, which encodes a G-protein-coupled receptor that plays a key role in maintaining hair growth and texture.
(3) Naxos disease An autosomal recessive disorder (OMIM:601214), first reported in a cohort on the Greek island of Naxos, which is characterised by palmoplantar keratoderma and other ectodermal defects and arrhythmogenic right ventricular dysplasia/cardiomyopathy.
Molecular pathology Naxos disease is caused by defects in JUP, which encodes a protein present in the submembranous plaques of desmosomes and intermediate junctions, which forms distinct complexes with cadherins.
(4) Woolly hair—autosomal dominant AN inherited condition (OMIM:194300) characterised by fine and tightly curled hair that grows slowly, stops growing after a few inches and, by light microscopy, has structural defects, including trichorrhexis nodosa and tapered ends.
Molecular pathology Defects in KRT74, which encodes a keratin specifically expressed in the inner root sheath of hair follicles.
Synonyms (for all of these conditions) Woolly hair disease, wooly hair disease, wooly hair syndrome