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.
Humans ; Infant, Newborn ; Acyltransferases/genetics* ; Ceramides/metabolism* ; Collodion ; Ichthyosis, Lamellar/genetics* ; Lipase/metabolism* ; Mutation ; Phospholipases/genetics*

OBJECTIVETo identify potential mutations in a Chinese collodion baby.

METHODSThe patient was investigated clinically. DNA was extracted from peripheral blood of the baby and his parents. All coding exons(exons 2-15) and splicing sites of transglutaminase 1(TGM1) were amplified by polymerase chain reaction (PCR). Mutation detection was performed by directed sequencing of the PCR products. A total of 100 healthy unrelated subjects were used as controls. Haplotypes were constructed with microsatellites flanking the locus, and TGM1 genotypes of the family were used to determine parental origins of the mutations. CLUSTAL X (1.81) was employed to analyze cross-species conservation of the mutant protein sequence.

RESULTSThe boy was found to be a compound heterozygote for two novel mutations: c.420A>G (I140M) from his father and c.832G>A (G278R) from his mother, with the former occurring in the transglutaminase N domain and the latter between transglutaminase N and transglutaminase-like domains. Both mutations were absent from the control subjects.

CONCLUSIONThe boy's condition was caused by two novel compound heterozygous mutations of c.420A>G and c.832G>A of TGM1. Author's results may provide new clues for molecular diagnosis of this disease.

Case-Control Studies ; China ; Heterozygote ; Humans ; Ichthyosis, Lamellar ; genetics ; Infant ; Male ; Mutation ; Pedigree ; Transglutaminases ; genetics

OBJECTIVETo explore the genetic cause for a Uyghur Chinese child with collodion skin.

METHODSG-banded chromosomal karyotyping was carried out for the child and his parents. High-throughput sequencing for 25 genes related to ichthyosis and ichthyosiform dermatosis was also performed for the child.

RESULTSNo karyotypic abnormality was found in the child and his parents. High-throughput sequencing has detected in the patient a previously described pathogenic mutation c.919C>T (p.Arg307Trp) and a novel c.856C>T (p.Arg286Trp) mutation in the TGM1 gene. By Sanger sequencing, the child was verified to have carried both mutations. His father was found to be a heterozygous carrier of the c.856C>T (p.Arg286Trp) mutation, while neither mutation was found in the mother.

CONCLUSIONCongenital ichthyosis associated with the TGM1 gene may show an autosomal recessive inheritance. The collodion condition of the child is probably due to the compound heterozygous mutations of the TGM1 gene.

Child ; Chromosome Banding ; Female ; High-Throughput Nucleotide Sequencing ; Humans ; Ichthyosis, Lamellar ; genetics ; Infant ; Karyotyping ; Mutation ; Transglutaminases ; genetics

OBJECTIVE: To explore the clinical and genetic characteristics of a pediatric patient suspected for Autosomal Recessive Congenital Ichthyosis (ARCI). METHODS: Clinical data of the patient was analyzed. Peripheral blood samples were collected from the patient and his parents for the extraction of genomic DNA. Next-generation sequencing (NGS) was then carried out. Candidate variants were confirmed by Sanger sequencing. A variety of bioinformatic tools including Mutation Taster, PROVEAN, and PolyPhen2 were used to predict the pathogenicity of the variants based on guidelines from the American College of Medical Genetics and Genomics (ACMG). RESULTS: The patient, a 1-month-and-7-day-old male, had presented with cutaneous erythema and fine scaling of the whole body. NGS revealed that he has harbored compound heterozygous variants c.1579G>A (p.Val527Met) (paternal) and c.923T>C (p.Leu308Pro) (maternal) of the ALOX12B gene. The former was known to be likely pathogenic, while the latter was unreported previously and categorized as "likely pathogenic" based on the ACMG guidelines. Based on the clinical and genetic findings, the patient was diagnosed with ARCI. CONCLUSION The c.1579G>A and c.923T>C variants of the ALOX12B genes probably underlay the ARCI in this patient. Above finding has enriched the spectrum of ALOX12B mutations and enabled molecular diagnosis of the patient, based on which genetic counseling and prenatal diagnosis may be provided.
Arachidonate 12-Lipoxygenase/genetics* ; Child ; Female ; Genes, Recessive ; Genetic Testing ; High-Throughput Nucleotide Sequencing ; Humans ; Ichthyosis, Lamellar/genetics* ; Male ; Mutation ; Pregnancy

OBJECTIVETo determine the mutations pattern of the genes of a collodion baby.

METHODSCollodion baby is a genetic heterogeneous disease caused by mutations of several genes. Since the most common mutations were observed in TGM1 gene, this gene was chosen for mutation screening. The screening was carried out by PCR and direct sequencing. The allele specific primers were designed for a missense mutation and allele-specific (AS) PCR was carried out in 50 normal individuals for population study.

RESULTSThree novel alterations were detected in TGM1 gene of the proband, a missense mutation c.463C > T (p.Arg155Trp) in exon 3, a nonsense mutation c.578G > A (p.Trp193X) in exon 4, and a single nucleotide deletion (c.694delG) also in exon 4 of TGM1 gene. This infant's father was heterozygote of c.694delG mutation, while his mother carried the two mutations (c.463C > T and c.578G > A) on the same chromosome. The missense mutation was not detected in his father and in any of the control individuals by AS-PCR.

CONCLUSIONThree novel mutations were identified in TGM1 gene in a Chinese collodion baby. A double mutation (c.463C > T and c.578G > A) located on the maternal allele while the c.694delG deletion on the paternal allele.

Alleles ; DNA Mutational Analysis ; Exons ; Genes, Recessive ; Genetic Testing ; Humans ; Ichthyosis, Lamellar ; genetics ; Male ; Point Mutation ; Polymerase Chain Reaction ; Sequence Analysis ; Sequence Deletion