Clinical variability in neurohepatic syndrome due to combined mitochondrial DNA depletion and Gaucher disease

Two siblings with Gaucher type 3c: different clinical presentations

Background Gaucher disease (GD) is a lysosomal storage disorder caused by autosomal recessive mutations in the glucocerebrosidase (GBA) gene, which encodes acid β-glucosidase. GD type 3c is a rare group characterised by cardiovascular involvement, and homozygous D448H is the most frequent mutation. Case presentation We describe two patients who had homozygous D448H mutations. The index patient had hepatosplenomegaly, liver insufficiency and cardiac involvement and her sister had severe cardiac involvement with cardiomyopathy and diffuse aortic calcification. The index case's liver was transplanted at the age of 6 months from a related donor and her sister who had severe cardiovascular disease died at the age of 12 years. Conclusions Our patients had clinical variability. We need to discuss whether liver involvement could be the initial signs in patients with GD type 3c.

A SUCLG1 mutation in a patient with mitochondrial DNA depletion and congenital anomalies

Defects in two subunits of succinate-CoA ligase encoded by the genes SUCLG1 and SUCLA2 have been identified in mitochondrial DNA (mtDNA) depletion syndromes. Patients generally present with encephalomyopathy and mild methylmalonic acidemia (MMA), however mutations in SUCLG1 normally appear to result in a more severe clinical phenotype. In this report, we describe a patient with fatal infantile lactic acidosis and multiple congenital anomalies (MCAs) including renal and cardiac defects. Molecular studies showed a defective electron transport chain (ETC), mtDNA depletion, and a novel homozygous mutation in the SUCLG1 gene. Although our patient's clinical biochemical phenotype is consistent with a SUCLG1 mutation, it is unclear whether the MCAs observed in our patient are a result of the SUCLG1 mutation or alterations in a second gene. An increasing number of reports have described MCAs associated with mitochondrial disorders and SUCLG1 specifically. Additional studies such as whole exome sequencing will further define whether additional genes are responsible for the observed MCAs.