We identified loss-of-function mutations in ATP6V0A2, encoding the a2 subunit of the V-type H+ ATPase, in several families with autosomal recessive cutis laxa type II or wrinkly skin syndrome. The mutations result in abnormal glycosylation of serum proteins (CDG-II) and cause an impairment of Golgi trafficking in fibroblasts from affected individuals. These results indicate that the a2 subunit of the proton pump has an important role in Golgi function.

Autosomal recessive cutis laxa (ARCL) describes a group of syndromal disorders that are often associated with a progeroid appearance, lax and wrinkled skin, osteopenia and mental retardation. Homozygosity mapping in several kindreds with ARCL identified a candidate region on chromosome 17q25. By high-throughput sequencing of the entire candidate region, we detected disease-causing mutations in the gene PYCR1. We found that the gene product, an enzyme involved in proline metabolism, localizes to mitochondria. Altered mitochondrial morphology, membrane potential and increased apoptosis rate upon oxidative stress were evident in fibroblasts from affected individuals. Knockdown of the orthologous genes in Xenopus and zebrafish led to epidermal hypoplasia and blistering that was accompanied by a massive increase of apoptosis. Our findings link mutations in PYCR1 to altered mitochondrial function and progeroid changes in connective tissues.

Juvenile hyaline fibromatosis (JHF) and infantile systemic hyalinosis (ISH) are autosomal recessive conditions characterized by multiple subcutaneous skin nodules, gingival hypertrophy, joint contractures, and hyaline deposition. We previously mapped the gene for JHF to chromosome 4q21. We now report the identification of 15 different mutations in the gene encoding capillary morphogenesis protein 2 (CMG2) in 17 families with JHF or ISH. CMG2 is a transmembrane protein that is induced during capillary morphogenesis and that binds laminin and collagen IV via a von Willebrand factor type A (vWA) domain. Of interest, CMG2 also functions as a cellular receptor for anthrax toxin. Preliminary genotype-phenotype analyses suggest that abrogation of binding by the vWA domain results in severe disease typical of ISH, whereas in-frame mutations affecting a novel, highly conserved cytoplasmic domain result in a milder phenotype. These data (1) demonstrate that JHF and ISH are allelic conditions and (2) implicate perturbation of basement-membrane matrix assembly as the cause of the characteristic perivascular hyaline deposition seen in these conditions.

Skin diseases are common in children. However, only a very few prospective epidemiologic surveys are available in the literature. The present survey was directed at determining the spectrum and pattern of skin diseases of children in Kuwait. A total of 10,000 consecutive new patients were studied; 96% were children of Arab descent. A female preponderance (52%) was observed, and infants constituted the largest group within the patient population (28.7%). A total of 162 dermatoses were recorded. Atopic dermatitis was the most prevalent dermatosis (31.3%), followed by viral warts (13.1%), alopecia areata (6.7%), pityriasis alba (5.25%), psoriasis (4%), and diaper dermatitis (4%). Atopic dermatitis was the most frequently seen dermatosis in children of all age groups, whereas, viral warts were more prevalent in school-age children. The prevalence of alopecia areata and psoriasis was higher than reported earlier in other ethnic groups. A female preponderance was seen in children with alopecia areata, psoriasis, vitiligo, acne vulgaris, contact dermatitis, and pityriasis rosea. Dermatitis, superficial cutaneous infections, and nevi/nevoid disorders were the important groups studied.

The study suggests that similar surveys from different regions would expand our understanding of ABD.