Complex heterozygous mutations in hereditary spherocytosis:A case report

BACKGROUND The aim of this study was to investigate the complex heterozygous mutations of ANK1 and SPTA1 in the same individual and improve our understanding of hereditary spherocytosis(HS)in children.We also hope to promote the application of gene detection technology in children with HS,with the goals of identifying more related gene mutations,supporting the acquisition of improved molecular genetic information to further reveal the pathogenesis of HS in children,and providing important guidance for the diagnosis,treatment,and prevention of HS in children.CASE SUMMARY A 1-year and 5-month-old patient presented jaundice during the neonatal period,mild anemia 8 months later,splenic enlargement at 1 year and 5 months,and brittle red blood cell permeability.Genetic testing was performed on the patient,their parents,and sister.Swiss Model software was used to predict the protein structure of complex heterozygous mutations in ANK1 and SPTA1.Genetic testing revealed that the patient harbored a new mutation in the ANK1 gene from the father and a mutation in the SPTA1 gene from the mother.Combined with the clinical symptoms of the children,it is suggested that the newly discovered complex heterozygous mutations of ANK1 and SPTA1 may be the cause,providing important guidance for revealing the pathogenesis,diagnosis,treatment,and promotion of gene detection technology in children with HS.CONCLUSION This case involves an unreported complex heterozygous mutation of ANK1 and SPTA1,which provides a reference for exploring HS.

Targeted next-generation sequencing identifies a novel nonsense mutation in ANK1 for hereditary spherocytosis:A case report

BACKGROUND Hereditary spherocytosis(HS)is characterized by anemia,jaundice,splenomegaly,and cholelithiasis,and is caused by abnormal genes encoding red blood cell membrane components.The most common mutations found in HS are in the ANK1 gene.CASE SUMMARY A 4-mo-old girl was admitted to our hospital with pallor that had lasted for more than 2 mo.She presented with jaundice,anemia and splenomegaly.A heterozygous mutation of ANK1(exon23:c.G2467T:p.E823X)was identified,and the mutation was determined to be autosomal dominant.This mutation is linked to the relatively serious anemia she had after birth;this anemia improved with age.CONCLUSION The utilization of next-generation sequencing may assist with the accurate diagnosis of HS,especially in atypical cases.

Exome sequencing confirms molecular diagnoses in 38 Chinese families with hereditary spherocytosis

Hereditary spherocytosis （HS）, the most common cause of congenital hemolytic anemia, is caused by deficiency of the ery- throcyte membrane proteins. Five causative genes （ANK1, SPTB, SPTA1, SLC4AI, and EPB42） have been identified. To date, molecular genetic studies have been performed in different populations, including the American, European, Brazilian, Japanese and Korean populations, whereas only a few studies have been described in the Chinese population. Here, by reanalysis of the exome data, we revealed causative mutations and established a definitive diagnosis of HS in all 38 Chinese families. We found 34 novel mutations and four reported mutations in three known HS-causing genes--17 in ANK1, 17 in SPTB and four in SLC4A1, suggesting that ANK1 and SPTB are the major genes in Chinese patients with HS. All of the ANK1 or SPTB mutations, scattered throughout the entire genes, are non-recurrent; and most of them are null mutations, which might cause HS via a hap-loinsufficiency mechanism. De novo mutations in ANK1 or SPTB often occur with an unexpected high frequency （87.5% and 64.2%, respectively）. Our study updates our knowledge about the genetic profile of HS in Chinese and shows that family-based, especially parent-offspring trio, sequencing analysis can help to increase the diagnostic power and improve diagnostic efficiency.