Autosomal recessive anhidrotic ectodermal dysplasia is an extremely rare condition. Clinical features include sparse hair, abnormal or missing teeth, and inability to sweat due to lack of sweat glands.
Mutations in the EDAR gene are now known to be causal.
Kabbaj et al. (1998) studied a large Moroccan family with autosomal recessive anhidrotic ectodermal dysplasia. Fourteen family members, both males and females, were affected and they all had a common ancestor.
In 1999, Baala et al. conducted linkage analysis on the DNA of the family members reported by Kabbaj et al. (1998). DNA was collected from 32 family members, including 8 affected children. After the exclusion of several chromosomal regions encompassing candidate genes, Baala et al. (1999) found linkage of the disease to the chromosome 2q11-q13 region in which a gene for dominant ectodermal dysplasia has been mapped.
Munoz et al. (1997) identified two female patients from the United Arab Emirates with possible autosomal recessive anhidrotic ectodermal dysplasia on the basis of the presence of severely affected females and unaffected consanguineous parents. An additional branch of the family, also consanguineous, had two affected females and one affected male among nine siblings. The disoredr in this family was found to be linked to the X chromosome.