Familial aggregation of alopecia areata.
BACKGROUND
Familial aggregation of alopecia areata (AA) has been previously described, but systematic studies with information obtained directly from family members have yet to be undertaken.


OBJECTIVE
We sought to study the pattern of familial aggregation of AA by assessing the affection status of patients' relatives. The study included 206 index patients with a total of 1029 first-degree and 2625 second-degree relatives.


METHODS
First-degree relatives were directly interviewed, whereas information on second-degree relatives was obtained by interviewing the index patients and their first-degree relatives.


RESULTS
Estimated lifetime risks were 7.1% in siblings, 7.8% in parents, and 5.7% in offspring. The risk in second-degree relatives was slightly higher than the reported population risk. Age at onset in index patients and first-degree relatives was significantly correlated.


CONCLUSIONS
Using patients drawn from specialized hair clinics may have produced results showing a higher proportion of early onset and severe cases.


CONCLUSIONS
The familial aggregation of AA supports the role of genetic factors in the development of the disease. In addition, our data indicate genetic factors might contribute to the age at onset of AA.
Blaumeiser
Bettina
B
Department of Medical Genetics, University Hospital of Antwerp, Antwerp, Belgium. bettina.blaumeiser@ua.ac.be
van der Goot
Ineke
I
Fimmers
Rolf
R
Hanneken
Sandra
S
Ritzmann
Sibylle
S
Seymons
Katia
K
Betz
Regina C
RC
Ruzicka
Thomas
T
Wienker
Thomas F
TF
De Weert
Jozef
J
Lambert
Julien
J
Kruse
Roland
R
Nöthen
Markus M
MM
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000506:Alopecia Areata / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005192:Family Health; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged