Is the loose anagen hair syndrome a keratin disorder? A clinical and molecular study.
OBJECTIVE
To report the clinical features of the loose anagen hair syndrome and to test the hypothesis that the typical gap between the hair and the inner root sheath may result from hereditary defects in the inner root sheath or the apposed companion layer.


METHODS
Case series.


METHODS
A pediatric dermatology unit (referral center).


METHODS
A consecutive sample of 17 children (13 girls). For 9 of them and their first-degree relatives, molecular analyses were performed in the K6HF gene with 50 appropriate controls.


METHODS
Minoxidil therapy (5% lotion) in 11 patients for 1 to 12 months.


METHODS
Clinical and follow-up features and determination of mutations in the K6HF gene.


RESULTS
Most patients had easily pluckable hair with no sign of scalp inflammation or scarring. Ten patients seldom cut their hair, and 4 had unmanageable hair. One patient had hypodontia. Two patients had an additional clinical phenotype of diffuse partial woolly hair. The family history was positive for loose anagen hair syndrome in 5 patients. Marked improvement was noted after treatment with 5% minoxidil lotion in 7 of the 11 patients treated. Polymerase chain reaction analysis of the gene segments encoding the alpha-helical 1A and 2B subdomains of K6hf, the type II cytokeratin exclusively expressed in the companion layer, was performed in 9 families. In 3 of these 9 families, a heterozygous glutamic acid and lysine mutation, E337K, was identified in the L2 linker region of K6HF.


CONCLUSIONS
Diffuse partial woolly hair can be associated with loose anagen hair syndrome. A keratin mutation, E337K in K6HF, was possibly causative in 3 of the 9 families studied. Another keratin, and possibly the type I partner of K6hf, could be responsible for loose anagen hair syndrome in other patients, or the gene involved may be a minor gene.
Chapalain
Valérie
V
Unité de Dermatologie Pédiatrique, Hôpital Pellegrin-Enfants, Bordeaux, France.
Winter
Hermelita
H
Langbein
Lutz
L
Le Roy
Jean-Michel
JM
Labrèze
Christine
C
Nikolic
Milos
M
Schweizer
Jürgen
J
Taïeb
Alain
A
D002648:Child; D002675:Child, Preschool; D005260:Female; D006201:Hair Diseases / Q000209:etiology*; D006801:Humans; D007633:Keratins; D008297:Male; D013577:Syndrome
D007633:Keratins