Hypotrichosis

Hypotrichosis
Classification and external resources
Specialty
ICD-9-CM	704.09
DiseasesDB	14765
Patient UK	Hypotrichosis
MeSH	D007039

Hypotrichosis (hypo- + tricho- + -osis) is a condition of abnormal hair patterns - predominantly loss or reduction. It occurs, most frequently, by the growth of vellus hair in areas of the body that normally produce terminal hair. Typically, the individual's hair growth is normal after birth, but shortly thereafter the hair is shed and replaced with sparse, abnormal hair growth. The new hair is typically fine, short and brittle, and may lack pigmentation. Baldness may be present by the time the subject is 25 years old.

Hypotrichosis is a common feature of Hallermann–Streiff syndrome as well as others. It can also be used to describe the lack of hair growth due to chemotherapy.

The opposite of hypotrichosis is hypertrichosis, where terminal hair (thick) grows in areas that would otherwise normally have vellus hair (thin), for example abnormally thick facial hair growth in women.

Genetic forms of localized autosomal recessive hypotrichosis include:

Type	OMIM	Gene	Locus
LAH1	607903	DSG4	18q12
LAH2	604379	LIPH	3q27
LAH3	611452	P2RY5	13q14.12-q14.2

See also

• List of conditions caused by problems with junctional proteins