Novel Pathogenic Mutation of PNPLA1 Identified in Autosomal Recessive Congenital Ichthyosis: A Case Report / 中国医学科学杂志(英文版)

Autosomal recessive congenital ichthyosis (ARCI) is characterized by being born as collodion babies, hyperkeratosis, and skin scaling. We described a collodion baby at birth with mild ectropion, eclabium, and syndactyly. Whole exome sequencing showed a compound heterozygous variant c.[56C>A], p.(Ser19X) and c.[100G>A], p.(Ala34Thr) in the PNPLA1 gene [NM_001145717; exon 1]. The protein encoded by PNPLA1 acts as a unique transacylase that specifically transfers linoleic acid from triglyceride to ω-hydroxy fatty acid in ceramide, thus giving rise to ω-O-acylceramide, a particular class of sphingolipids that is essential for skin barrier function. The variant was located in the patatin core domain of PNPLA1 and resulted in a truncated protein which could disrupt the function of the protein. This case report highlights a novel compound heterozygous mutation in PNPLA1 identified in a Chinese child.

Allelic variation of GSTT1, GSTM1 and GSTP1 genes in North Indian population.

Glutathione S-transferase (GST) enzymes are involved in detoxification of many potentially carcinogenic compounds. Homozygous deletions or null genotypes of GSTT1 and GSTM1 genes and an A to G substitution at nucleotide 313 in GSTP1 have been reported in different populations. Intra-ethnic as well as interethnic differences are known to exist in the frequencies of the above GST genes. The present study was therefore undertaken to determine the prevalence of GSTM1 and GSTT1null alleles, as well as the GSTP1 gene polymorphism, in 370 healthy individuals in a North Indian population. Genotyping of M1 and T1 was performed using a multiplex polymerase chain reaction and the GSTP1 polymorphism was determined by the polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) method. The frequencies of GSTM1 and GSTT1 null alleles in normal healthy individuals were observed to be 33.0% and 18.4% respectively. In 7.0% of individuals' concomitant lack of M1 and T1 genes were observed. For GSTP1, wild (Ile/Ile), heterozygous (Ile/Val) and mutant (Val/Val) genotypes were observed for 44.3%, 50.3% and 5.4% of individuals respectively. The prevalence of the M1 null allele is significantly lower than those documented for English, Turkish, Chinese, Caucasians, Japanese and white (Brazilian and American) populations. However, a significantly higher frequency for T1 null was reported in Chinese and Japanese population. Furthermore, Japanese and African American populations have exhibited significantly higher frequencies of wild and mutant P1 genotypes, respectively, than the Indian population. Thus, our results signify an impact of ethnicity and provide a basis for future epidemiological and clinical studies.