A novel splice site indel alteration in the EIF2AK3 gene is responsible for the first cases of Wolcott-Rallison syndrome in Hungary

BACKGROUND

Wolcott-Rallison Syndrome (WRS) is a rare autosomal recessive disease that is the most common cause of neonatal diabetes in consanguineous families. WRS is caused by various genetic alterations of the Eukaryotic Translation Initiation Factor 2-Alpha Kinase 3 (EIF2AK3) gene.

METHODS

Genetic analysis of a consanguineous family where two children were diagnosed with WRS was performed by Sanger sequencing. The altered protein was investigated by in vitro cloning, expression and immunohistochemistry.

RESULTS

The first cases in Hungary, - two patients in one family, where the parents were fourth-degree cousins - showed the typical clinical features of WRS: early onset diabetes mellitus with hyperglycemia, growth retardation, infection-induced multiple organ failure. The genetic background of the disease was a novel alteration in the EIF2AK3 gene involving the splice site of exon 11- intron 11-12 boundary: g.53051_53062delinsTG. According to cDNA sequencing this created a new splice site and resulted in a frameshift and the development of an early termination codon at amino acid position 633 (p.Pro627AspfsTer7). Based on in vitro cloning and expression studies, the truncated protein was functionally inactive. Immunohistochemistry revealed that the intact protein was absent in the islets of pancreas, furthermore insulin expressing cells were also dramatically diminished. Elevated GRP78 and reduced CHOP protein expression were observed in the liver.

CONCLUSIONS

The novel genetic alteration causing the absence of the EIF2AK3 protein resulted in insufficient handling of severe endoplasmic reticulum stress, leading to liver failure and demise of the patients.

EIF2AK3 novel mutation in a child with early-onset diabetes mellitus, a case report

Background

Wolcott-Rallison syndrome (WRS) is caused by a biallelic mutation in the gene encoding eukaryotic translation initiation factor 2-alpha kinase 3 (EIF2AK3) on chromosome 2p11.2. This condition is characterized by permanent early-onset diabetes mellitus, epiphyseal dysplasia, and hepatic dysfunction. We report a patient with WRS born to a consanguineous marriage due to a novel biallelic frameshift mutation in the EIF2AK3 gene.

Case presentation

Our patient was a 2-year-and-6-month-old Yemeni girl born to consanguineous parents who was diagnosed with neonatal diabetes at 20 days of age. She presented with chronic diarrhea and liver dysfunction. The child was normocephalic and exhibited failure to thrive and hepatomegaly with no skeletal deformities. Further investigations revealed microcytic anemia, liver impairment and primary hypothyroidism. Genetic testing confirmed the diagnosis of WRS via identification of a novel biallelic frameshift mutation in the EIF2AK3 gene. During her hospital stay, she went into septic shock and developed multi-organ failure, including fulminant hepatic failure. She unfortunately died within 2 weeks of her hospital stay.

Conclusions

Wolcott-Rallison syndrome is recognized as the most common cause of early-onset diabetes in infants born to consanguineous marriages. Screening for genetic mutations in EIF2AK3 is recommended for establishing early diagnosis, providing genetic counselling, and predicting the development of additional clinical features, most importantly hepatic failure. Hence, this screening is important for guiding optimal management and improving patient outcome.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1432-8) contains supplementary material, which is available to authorized users.