Hypotrichosis simplex

Alternate names

HHS

Definition

Hypotrichosis simplex is a rare form of hereditary hair loss without other abnormalities. Affected individuals typically show normal hair at birth, but experience hair loss and thinning of the hair shaft that starts during early childhood and progresses with age.

Cause

Some cases are caused by mutations in the APCDD1 gene on chromosome 18p11.

Inheritance

Hypotrichosis simplex can be inherited either as an autosomal dominant or autosomal recessive trait.

Types

Hypotrichosis simplex can be divided into 2 forms: the scalp-limited form and the generalized form, in which all body hair is affected.

Signs and symptoms

Affected individuals typically show normal hair at birth, but experience hair loss and thinning of the hair shaft that starts during early childhood and progresses with age. The progressive thinning of the hair shaft is a typical feature of androgenetic alopecia.

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Alopecia(Hair loss)
• Sparse and thin eyebrow (Thin, sparse eyebrows)
• Sparse body hair
• Sparse eyelashes(Scanty eyelashes)
• Sparse scalp hair(Reduced/lack of hair on scalp)

1%-4% of people have these symptoms

• Sparse axillary hair(Limited armpit hair)
• Sparse eyebrow(Sparse eyebrows)
• Sparse pubic hair(Decreased sexual hair)

Diagnosis

Scalp skin biopsy reveals a decreased number of follicles, especially in the telogen phase, with no specific pattern and no structural changes.[1].

Treatment

• Individuals with hypotrichosis simplex experience a gradual loss of scalp hair that begins during the middle of the first decade and results in almost complete loss of hair by the third decade.
• A few sparse, fine, short hairs may remain in some individuals.
• There is currently no treatment for hypotrichosis simplex.

NIH genetic and rare disease info

• NIH info on Hypotrichosis simplex

Hypotrichosis simplex is a rare disease.