RESUMO
OBJECTIVE@#To analyze gene variants in a Chinese pedigree with oculocutaneous albinism (OCA).@*METHODS@#Gene sequencing of the proband and his parents was performed using chip capture high-throughput sequencing and Sanger sequencing techniques, and PolyPhen-2, SIFT, MutationTaster, and FATHMM software were used to predict the function of new variants. At the same time,the pedigree and variant genes of 4 albinism patients from this pedigree were analyzed.@*RESULTS@#Sequencing results showed that the proband's TYR gene (NM_000372) has c.230G>A (p.Arg77Gln) and c.120_121insG (p.Asp42GlyfsTer35) compound heterozygous variants. The proband's father carries c.230G>A heterozygous variant, and the mother carries c.120_121insG heterozygous variant, indicating that the proband's two variants are from his father and mother. The former is a known missense variant, which can cause abnormal or loss of the original function of the protein polypeptide chain. The latter c.120_121insG(p.Asp42GlyfsTer35) is an unreported frameshift variant of the TYR gene subregion (EX1; CDS1). PolyPhen-2, SIFT, MutationTaster and FATHMM predictions are all prompted as "harmful variants". This variant caused the amino acid encoded protein to terminate prematurely, producing a truncated protein, which eventually formed a 76-amino acid short-type TYR protein instead of the 529-amino acid wild-type TYR protein. Through the pedigree analysis, the four patients in the pedigree are all of the same type of compound heterozygous variants, and the disease-causing genes are all from the patient's parents. They belong to a special form of consanguineous marriage within 5 generations.@*CONCLUSION@#The compound heterozygous variants of c.230G>A (p.Arg77Gln) and c.120_121insG (p.Asp42GlyfsTer35) of the TYR gene may underlie the disease in this pedigree. The gene sequencing results enrich the variant spectrum of the TYR gene, and has facilitated molecular diagnosis for the patient.
Assuntos
Humanos , Albinismo Oculocutâneo/genética , Consanguinidade , Heterozigoto , Mutação , LinhagemRESUMO
Objective To develop a method for detecting the genotype of Plasmodium vivax merozoite surface protein 1 (PvMSP-1) alleles. Methods According to the sequence characteristic of PvMSP-1, nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used to amplify the polymorphic region of ICB5-ICB6 which contains Q repeats and PvuII restriction site (Sal-1 type). The PCR product was digested by PvuII restriction endonuclease and the digested fragments were observed by 2% agarose gel electrophoresis. The allelic type was determined according to the banding pattern. Results Bands in size of 400 bp (Belem type ) and/or 470 bp (Sal-1 type ) appeared in all 98 P. vivax isolates, no band was found in negative control. After PvuII digestion, two Sal-1 type fragments (120 bp and 350 bp) were obtained from 45 samples of 470 bp. Single-band of 400 bp appeared in 3 of 40 samples with 400 bp as Belem type, two bands of 120 bp and 280 bp appeared from other 35 samples as recombination type III, and another 2 bands with 120 bp and 240 bp as Korean isolate. Conclusion The result showed that the nested PCR-RFLP may be applied in the detection and identification of the three PvMSP-1 allelic types in China.
