ABSTRACT
Keratosis follicularis spinulosa decalvans (KFSD) is a rare X-chromosomal disorder. It consists of follicular hyperkeratosis of the skin, scarring alopecia of the scalp, absence of the eyebrows, and corneal degeneration. There is photophobia in childhood, but the symptoms tend to diminish after puberty, and prognosis for vision is good. Some heterozygotes do show clinical symptoms. In a large Dutch pedigree we performed DNA analysis in order to localize the KFSD gene. In 54 individuals, including 21 affected males, RFLP analysis was done using DNA probes covering the X chromosome. Two-point linkage analyses with 19 informative DNA markers revealed significant linkage to DNA probes on Xp21.1-p22.3. The highest lod scores of 5.70 and 4.38 were obtained with DXS41 and DXS16 at a recombination fraction of zero and 4 cM, respectively. Multipoint linkage data place KFSD between DXS16 and DXS269. Our data confirm X linkage of KFSD in this family and tentatively map the gene on Xp22.2-p21.2. Combined with clinical investigation, RFLP analysis may become an important tool in carrier detection.
Subject(s)
Darier Disease/genetics , Genetic Linkage/genetics , X Chromosome , Chromosome Mapping , DNA Probes , Darier Disease/enzymology , Female , Humans , Male , Netherlands , PedigreeABSTRACT
In a large Dutch family with keratosis follicularis spinulosa decalvans (KFSD, MIM 308800), DNA linkage analysis was performed in order to locate the gene. Pedigree analysis and lod score calculation confirmed X-linked inheritance and revealed significant linkage to DNA markers on Xp. A maximum lod score of 5.70 at theta = 0.0 was obtained with DXS41 (p99.6). The KFSD gene is tentatively located on Xp21.2-p22.2.
Subject(s)
Darier Disease/genetics , Genetic Linkage/genetics , X Chromosome , Chromosome Mapping , DNA/analysis , DNA Probes , Female , Genetic Carrier Screening , Humans , Lod Score , Male , Netherlands , Pedigree , Polymorphism, Restriction Fragment LengthABSTRACT
Keratosis follicularis spinulosa decalvans (KFSD) is a rare X linked disease which is characterised by follicular hyperkeratosis of the skin and corneal dystrophy. Seven male patients and six female carriers are described. Special attention has been paid to the dermatological and ophthalmic markers of KFSD in patients and carriers. The most prominent features present in the male patients were follicular hyperkeratosis, hyperkeratosis of the calcaneal regions of the soles, scarring alopecia of the scalp, absence of eyebrows and eyelashes, and corneal dystrophy accompanied by photophobia. They also had high cuticles on the fingernails which has not been described before. Carriers often have dry skin, minimal follicular hyperkeratosis, and mild hyperkeratosis of the calcaneal areas of the soles. Mild corneal dystrophy without photophobia was observed in one female carrier.
