AUTHOR=Kang Pengjiang , Zhang Weihua , Wen Jinquan , Zhang Jiming , Li Fei , Sun Wuxia 

TITLE=Case Report: Genetic and Clinical Features of Maternal Uniparental Isodisomy-Induced Thiamine-Responsive Megaloblastic Anemia Syndrome

JOURNAL=Frontiers in Pediatrics

VOLUME=Volume 9 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2021.630329

DOI=10.3389/fped.2021.630329

ISSN=2296-2360

ABSTRACT=Background: Thiamine-responsive megaloblastic anemia syndrome (TRMA) is a rare autosomal recessive hereditary disease with mutations in SLC19A2. Some cases with it are related by familial inheritance.
Case report: A female patient (G1P1) aged 3 years and 6 months was admitted to the Pediatric Hematology Department of Xianyang Caihong Hospital in June 2019. The patient had severe anemia, acupoint-sized bleeding spots, and a few ecchymoses all over her body, as well as astigmatism and hyperopia, but her binaural hearing was normal. The patient had diabetes. Bone marrow biopsy suggested myelodysplastic syndrome. The patient had a C.515G>A (P.G 172D) homozygous mutation of SLC19A2 (NM006996), indicating TRMA. Genetic testing revealed a region of homozygosis inherited from her mother alone and induced by maternal UPD. The patient was treated with thiamine and subcutaneous injection of insulin. The patient recovered well and was discharged. She continued thiamine and insulin at the same dose and review once a month. The last follow-up on September 15, 2020, showed no anemia or bleeding; she had sound hearing and normal blood routine indexes and fasting glucose levels, although her hyperopia and astigmatism had no significant improvement.
Conclusion: The patient had TRMA induced by maternal-UPD-involved C.515G>A (P. G172D) homozygous mutation of SLC19A2. The genetic diagnosis of TRMA is of significance for guiding clinical treatment. Early treatment with exogenous thiamine can improve some of the clinical features of TRMA.