GALNS Gene Exists In Chinese Patient With Mucopolysaccharidosis ⅣA

Objective:Mucopolysaccharide diseases Ⅳ type A (MPS ⅣA) is a rare hereditarymetabolic disorder due to the loss of GALNS enzyme activity or function defects.Major clinical manifestations for stunting, ugly face, skeletal deformities, abnormalgait, liver and spleen enlargement, corneal opacity, etc., but intelligence is normal.The present study suggests that this disease have a significant genetic predisposition,is recessive inheritance disease. In this study,we will use the extraction of humangenomic DNA, PCR amplification and DNA sequence analysis to scan all fourteenexons and adjacent intron regions of MPS ⅣApathogenicity-related gene GALNS inorder to obtain exact types of mutations of gene GALNS.Preliminary analysis of therelationship between genotype and phenotype of the MPS ⅣA patients provide datafor the MPS ⅣA molecular etiology studies to help MPS ⅣA patients with geneticdiagnosis, genetic treatment,prenatal diagnosis and genetic counseling.Methods:Using the blood genomic DNAextraction kit producted by TIANGEN company,total genomic DNA was extracted from the peripheral blood leukocytes of the MPSⅣApatient and50unrelated healthy controls. All14exon sequence(NT-010542) andcDNA sequence(NM-000512) of GALNS gene was get in genatlas.We consulteddocuments and used primer3software designed to14pairs of primers which coversall14exons of GALNS gene.Polymerase chain reaction (PCR) amplification allfourteen exons and the surrounding parts of the introns of GALNS gene. PCRproducts are sequenced by direct DNA sequencing with the forward and reverse primers. Refer to the existing domestic and international studies and reports, therelationship between the MPS ⅣA genotype and phenotype will be preliminaryanalyzed.Results:No reported and new mutations in the all14exons of GALNS gene were foundin the sporadic case. But, two GALNS gene polymorphisms were identified,1431A＞G,1569+36A＞G, in the patient and controls.These two gene polymorphisms arehomozygous.And these two gene polymorphisms had reported in the SNP databasewhich belongs to NCBI.Conclusion:1.Mutations in the GALNS gene is not major cause of MPS ⅣA in the patientin the study.2. The children detected2GALNS gene polymorphisms, and consistent with theresults announced the SNP database.3. For the MPS IVAfamily which found no gene mutations but detected the genepolymorphism,how to carry out genetic diagnosis, gene therapy, prenatal disgnosisand genetic counseling, will be studied further.