Mutations in PYCR1 cause cutis laxa with progeroid features.
; ; et al
in Nature Genetics (2009), 41(9), 1016-21
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 ... [more ▼]
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. [less ▲]Detailed reference viewed: 44 (3 ULg)
Novel types of mutation responsible for the dermatosparactic type of Ehlers-Danlos syndrome (Type VIIC) and common polymorphisms in the ADAMTS2 gene.
Colige, Alain ; ; et al
in The Journal of investigative dermatology (2004), 123(4), 656-63
Ehlers-Danlos syndrome (EDS) type VIIC, or dermatosparactic type, is a recessively inherited connective tissue disorder characterized, among other symptoms, by an extreme skin fragility resulting from ... [more ▼]
Ehlers-Danlos syndrome (EDS) type VIIC, or dermatosparactic type, is a recessively inherited connective tissue disorder characterized, among other symptoms, by an extreme skin fragility resulting from mutations inactivating ADAMTS-2, an enzyme excising the aminopropeptide of procollagens type I, II, and III. All previously described mutations create premature stop codons leading to a marked reduction in the level of mRNA. In this study, we analyzed the ADAMTS2 cDNA sequences from five patients displaying clinical and/or biochemical features consistent with a diagnosis of either typical or potentially mild form of EDS type VIIC. Three different alterations were detected in the two patients with typical EDS type VIIC. The first patient was homozygous for a genomic deletion causing an in-frame skipping of exons 3-5 in the transcript. In the second patient, the allele inherited from the mother lacks exon 3, generating a premature stop codon, whereas the paternal allele has a genomic deletion resulting in an in-frame skipping of exons 14-16 at the mRNA level. Although the exons 3-5 or 14-16 encode protein domains that have not been previously recognized as crucial for ADAMTS-2 activity, the aminoprocollagen processing was strongly impaired in vitro and in vivo, providing evidence for the requirement of these domains for proper enzyme function. The three other patients with a phenotype with some resemblance to EDS type VIIC only had silent and functionally neutral variations also frequently found in a normal population. [less ▲]Detailed reference viewed: 23 (2 ULg)
The natural history, including orofacial features of three patients with Ehlers-Danlos syndrome, dermatosparaxis type (EDS type VIIC).
; ; et al
in American Journal of Medical Genetics. Part A (2004), 131(1), 18-28
Ehlers-Danlos syndrome (EDS) dermatosparaxis type (type VIIC) and the related disease of cattle dermatosparaxis, are recessively inherited connective tissue disorders, caused by a deficient activity of ... [more ▼]
Ehlers-Danlos syndrome (EDS) dermatosparaxis type (type VIIC) and the related disease of cattle dermatosparaxis, are recessively inherited connective tissue disorders, caused by a deficient activity of procollagen I N-proteinase, the enzyme that excises the N-terminal propeptide in procollagen type I, type II, and type III. Although well documented in cattle, to date only seven human cases have been recorded, most of them aged under 2 years. We document the natural history of three patients with EDS dermatosparaxis type, two of whom have been reported before the age of 2 years, and one new patient. The phenotype of the patients, and especially the facial resemblance, is striking, making this a clinically recognizable condition. The most consistent anomalies during the first years of life are premature rupture of the membranes, extreme skin fragility and easy bruising, large fontanels, blue sclerae, puffy eyelids, micrognathia, umbilical hernia, and short fingers. Joint hypermobility becomes more important with age. The children are at risk for rupture of internal organs due to soft tissue fragility, as is illustrated by different internal events in two of the three patients described here. Orofacial features include micrognathia, a frontal open bite, and gingival hyperplasia with varying degrees of hyperkeratosis. The deciduous dentition shows abnormal morphology of the molars, obliteration of the tooth pulp, and severe enamel attrition. The permanent dentition shows agenesis and microdontia of several teeth. Tooth discoloration, dysplastic roots, and tooth pulp obliteration are present in a restricted number of permanent teeth. [less ▲]Detailed reference viewed: 17 (1 ULg)