Based On High Throughput Sequencing To Genetic Analysis In A Late-onset Pompe Family

Pompe disease?acid maltose deficiency,glycogen storage syndrome type II?is an autosomal recessive genetic disease,caused by a deficiency of lysosomal acid ?-1,4-glucosidase,a large amount of glycogen cannot be degraded in the body,which is formed by the accumulation of glycogen in tissue cells such as skeletal muscle,myocardium and smooth muscle.Pompe disease is essentially a rare multisystem disease caused by pathological changes in alpha-glucosidase?GAA?.In this study,the purpose was to identify the pathogenic variation,as well as the relationship between intestinal microbial structure and disease phenotype,in a family with late-onset Pompe disease with cerebral infarction and leukoencephalopathy.In this study,WGS sequencing was performed on 6 normal individuals,2 sick individuals and 1 suspected child in a Chinese family,and biological information analysis was applied to identify candidate pathogenic variation.The results of sanger sequencing and enzyme activity were verified,we further analyzed the relationship between mutation and phenotype.In order to explain the abnormality of child in female patients,Meta sequencing and analysis were used to explore the relationship between disease phenotype and intestinal microorganism.After sequencing and analysis,the 9 family members of the Chinese family?including 2 patients and 1 suspected child?genomes,a new complex heterozygous mutation was found,c.2238G>C at exon 16 of GAA gene and c.1388₁406del19 at exon 9,which was the cause of Pompe disease in this family.One of the complex heterozygous mutations was missense mutation c.2238G>C?p.Trp746Cys?from the patient's father,and the other was shift code mutation c.1388₁406del19?p.Arg463fs?form the mother.The mutation of c.2238G>C?p.Trp746Cys?will lead to the mutation of codon 746 from non-polar tryptophan to polar cysteine,affecting the function of acidic alpha-glucosidase.c.1388₁406del19?p.Arg463fs?is a shift deletion mutation that causes early termination of protein translation at 462 amino acids.The results of the Metagenomics analysis showed that the intestinal flora of female's child was abnormal at birth,but returned to normal later,which possibly due to the influence of the mother's intestinal microorganisms.Combined with genomic information,we can conclude that the female's child is the carrier,but since the other homologous chromosome is normal,she will not get the disease.In conclusion,these novel compound heterozygous mutations in GAA gene was the first time in a Chinese family,our finding has enriched the gene mutation spectrum of Pompe disease,provided support for the study of the relationship between disease phenotype and mutation.The use of intestinal flora to explain phenotypic abnormalities and complications for the first time may be a very favorable direction and provide a new perspective for disease research.