Hereditary intrinsic factor deficiency in China caused by a novel mutation in the intrinsic factor gene\u2014a case report

Jing Ruan,Junling Zhuang,Wenzhe Zhou,Yuzhou Huang,Fangfei Chen,Bing Han,Miao Chen

doi:10.1186/s12881-020-01158-z

Jing Ruan, Junling Zhuang + Show 5 more

Open Access

https://doi.org/10.1186/s12881-020-01158-z

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Abstract

BackgroundHereditary intrinsic factor deficiency is a rare disease characterized by cobalamin deficiency with the lack of gastric intrinsic factor because of gastric intrinsic factor (GIF) mutations. Patients usually present with cobalamin deficiency without gastroscopy abnormality and intrinsic factor antibodies.Case presentationA Chinese patient presented with recurrent severe anemia since age 2 with low cobalamin level and a mild elevation of indirect bilirubin. The hemoglobin level normalized each time after intramuscular vitamin B12 injection. Gene test verified a c.776delA frame shift mutation in exon 6 combined with c.585C > A nonsense early termination mutation in exon 5 of GIF which result in the dysfunction of gastric intrinsic factor protein. The hereditary intrinsic factor deficiency in literature was further reviewed and the ancestry of different mutation sites were discussed.ConclusionsA novel compound heterozygous mutation of GIF in a Chinese patient of hereditary intrinsic factor deficiency was reported. It was the first identified mutation of GIF in East-Asia and may indicate a new ancestry.

Highlights

Hereditary intrinsic factor deficiency is a rare disease characterized by cobalamin deficiency with the lack of gastric intrinsic factor because of gastric intrinsic factor (GIF) mutations
Vitamin B12 or cobalamin deficiency is characterized by megaloblastic anemia with neurological problems and can be caused by numerous acquired and inherited diseases [1]
intrinsic factor deficiency (IFD) is caused by homozygous or compound heterozygous mutation in the gene of gastric intrinsic factor on chromosome 11q12. It presents in early childhood with the lack of gastric intrinsic factor, while the gastric acid secretion is normal and no autoantibody to intrinsic factor is found

Summary

Introduction

Hereditary intrinsic factor deficiency is a rare disease characterized by cobalamin deficiency with the lack of gastric intrinsic factor because of gastric intrinsic factor (GIF) mutations. Conclusions: A novel compound heterozygous mutation of GIF in a Chinese patient of hereditary intrinsic factor deficiency was reported. Background Vitamin B12 or cobalamin deficiency is characterized by megaloblastic anemia with neurological problems and can be caused by numerous acquired and inherited diseases [1]. Two hereditary diseases have been found to cause cobalamin malabsorption including Imerslund-Grasbeck syndrome (IGS) and hereditary intrinsic factor deficiency (IFD) [2].

Results

Conclusion