APA (Old Order Amish; Eastern Pennsylvania)

Inheritance: autosomal dominant
Genes: unknown

Hypertrichosis cubiti

Hypertrichosis
Hairy elbows
Short stature
Developmental delay
Shortened nails

Hairy Elbows

Clinical Characteristics

General description (for patients):

This is a rare condition with localized hairiness of the upper forearms and the elbow region. Infants have excessive hair in this region but of the fine type which becomes coarser until adolescence when it regresses somewhat.  The fingernails are shortened and the facies may be unusual with heavy-set jaws.  Some mild developmental delay may be present.

Medical description:  

This is a rare condition of localized hypertrichosis in the elbow region, involving the lower third of the upper arm and the upper third of the lower arm.  It is progressive in early childhood, with some regression during adolescence.  Short stature, prominent mandibles, shortened nails, and mild developmental delay have been noted as well.  No teeth abnormalities or associated systemic disease has been found.

Genetics:

This may be an autosomal dominant disorder but insufficient numbers of patients have been reported to be certain.  The molecular defect has not been found.  A single family with two affected sibs has been reported in the Amish of Eastern Pennsylvania.  Interestingly, PKU also segregated in this family with two additional sibs affected.

Treatment:

None necessary.

Prognosis:

Excellent.                

Ancillary treatments and support:

None necessary.

Specialists and specialty centers:

Dermatologist.

References:

Beighton, P.H.:  Familial hypertrichosis cubiti: hairy elbows syndrome.  J. Med. Genet. 7: 158-160, 1970.  PubMed ID: 5519603

Visser, R., Beemer, F.A., Veenhoven, R.H. and De Nef, J.J.E.M.:  Hypertrichosis cubiti: two new cases and a review of the literature.  Genet. Counsel. 13: 397-403, 2002.  PubMed ID: 12558109