Introduction: Bi-allelic mutations in the TRMU gene cause reversible infantile liver failure. Little is known about extra-hepatic manifestations in these patients.
Background: Two infants, aged 4 and 5 months, presented with progressive life threatening liver failure, characterized by lactic acidosis, highly elevated alpha-fetoprotein and recurrent hypoglycemia. Both showed significant extra-hepatic findings, including: hypothyroidism, macrocytic anemia and microcephaly. Both were of Jewish Yemenite descent and homozygous for Y77H mutation in the TRMU gene.
Conclusions: TRMU bi-allelic mutations cause severe life-threatening liver failure. Extra-hepatic involvement is common and should be evaluated. Spontaneous resolution and recovery occurs in most patients with a remarkably good long-term prognosis. Liver failure in a Jewish-Yemenite infant should prompt early genetic testing for TRMU Y77H mutation. Pediatricians should be aware of this disease and the common mutation in Israel.
Discussion: Nineteen additional patients were described in the literature, of whom 13 were from Israel; 6/19 (31%) manifested extra-hepatic involvement, namely: myopathic weakness, cardiomyopathy, renomegaly and proteinuria, bulbar dysfunction, cerebral white matter changes and abnormal growth including microcephaly. Mortality was 24% (5/21). Survivors (16/21, 76%) showed complete recovery and resolution of clinical, laboratory and histologic abnormalities. Most Israeli patients (10/15) were of Jewish-Yemenite ancestry. Homozygous Y77H genotype was exclusive to this patient subgroup and was associated with a 100% survival and recovery rate.