Conversely, alleles of <i>ABHD5</i> carrying point mutations associated with ichthyosis in humans failed to accelerate PNPLA1-mediated AcylCer biosynthesis.
Notably, topical application of epidermal lipids from wild-type onto Pnpla1-mutant mice promoted rebuilding of the corneocyte-bound lipid envelope, indicating that supplementation of ichthyotic skin with omega-O-acylceramides might be a therapeutic approach for the treatment of skin symptoms in individuals affected by omega-O-acylceramide deficiency.
Mutations in connexin 26 are linked to diseases including Vohwinkel syndrome, keratitis-ichthyosis deafness, and hystrix-like ichthyosis deafness syndromes, palmoplantar keratoderma with deafness, deafness with Clouston-like phenotype, and Bart-Pumphrey syndrome.
In addition, whole exome sequencing approach also solved the genetics of some syndromic forms of PAI including IMAGe syndrome (<i>CDKN1C</i>), Irish traveler syndrome (<i>MCM4</i>), MIRAGE syndrome (<i>SAMD9</i>); and most recently a syndrome combining FGD with steroid-resistant nephrotic syndrome and ichthyosis caused by mutations in the gene for sphingosine-1-phosphate lyase 1 (<i>SGPL1</i>).
Clinically typical phenotype of the TGM1 mutation carrier includes large, thick, brownish scales, but ichthyosis of some of these patients tends to be milder.
The TGM1 mutation spectrum was characterised and genotype-phenotype correlations investigated in 104 patients with ARCI ascertained through the National Registry for Ichthyosis and Related Disorders in the USA.
STS deficiency (STSD) due to deletions or inactivating mutations in the X-linked STS gene manifests with ichthyosis, but androgen synthesis and metabolism in STSD have not been studied in detail yet.
Two independent familial STS deletions, one of which is associated with a phenotype of ichthyosis plus ocular albinism (XI/OA1) and the other with nystagmus plus Rud syndrome, lack some but not all of the normal S232 PFGE fragments.
Recent work has shown that a number of diseases which display defective epidermal barrier function, generically known as ichthyoses, are the result of genetic defects of the synthesis of either CE proteins, the transglutaminase 1 cross-linking enzyme, or defective metabolism of skin lipids.
X-linked ichthyosis is a relatively common syndromic form of ichthyosis most often due to deletions in the gene encoding the microsomal enzyme, steroid sulfatase, located on the short area of the X chromosome.
Combined with data from the literature, these findings confirm the hypothesis that only a restricted spectrum of TGM1 mutations leads to a BSI and/or an SICI phenotype.
Self-improving collodion ichthyosis occurred in 8% of the cases (mostly TGM1 and ALOX12B mutations) but could not be predicted precisely from neonatal phenotype or genotype.
The study was made up of three groups including 9 Ichthyosis vulgaris (IV) patients, 50 AD patients and 55 normal controls: the ichthyosis group was incorporated due to the reported association between the FLG mutation and IV.
These studies extend our prior work on TGM1-deficient LI to the full spectrum of TGM1-deficient patients, showing that the CIE phenotype, when attributable to a V518M heterozygous mutation in TGM1 in combination with an inactive allele, confers a cross-linking deficiency in a variety of keratinizing epithelia, as previously shown for TGM1-negative LI.
The identification of mutations in the transglutaminase-1 gene as a cause of lamellar ichthyosis implicates transglutaminases in other congenital recessive ichthyoses.
The TGM1 mutation spectrum was characterised and genotype-phenotype correlations investigated in 104 patients with ARCI ascertained through the National Registry for Ichthyosis and Related Disorders in the USA.