Genotypic and phenotypic spectrum of infantile liver failure due to pathogenic TRMU variants.

PURPOSE: This study aimed to define the genotypic and phenotypic spectrum of reversible acute liver failure (ALF) of infancy resulting from biallelic pathogenic TRMU variants and determine the role of cysteine supplementation in its treatment. METHODS: Individuals with biallelic (likely) pathogenic variants in TRMU were studied within an international retrospective collection of de-identified patient data. RESULTS: In 62 individuals, including 30 previously unreported cases, we described 47 (likely) pathogenic TRMU variants, of which 17 were novel, and 1 intragenic deletion. Of these 62 individuals, 42 were alive at a median age of 6.8 (0.6-22) years after a median follow-up of 3.6 (0.1-22) years. The most frequent finding, occurring in all but 2 individuals, was liver involvement. ALF occurred only in the first year of life and was reported in 43 of 62 individuals; 11 of whom received liver transplantation. Loss-of-function TRMU variants were associated with poor survival. Supplementation with at least 1 cysteine source, typically N-acetylcysteine, improved survival significantly. Neurodevelopmental delay was observed in 11 individuals and persisted in 4 of the survivors, but we were unable to determine whether this was a primary or a secondary consequence of TRMU deficiency. CONCLUSION: In most patients, TRMU-associated ALF was a transient, reversible disease and cysteine supplementation improved survival.

Percutaneous endoscopic gastrostomy for refractory epilepsy and medication refusal.

OBJECTIVE: Current guidelines for percutaneous endoscopic gastrostomy (PEG) placement focus largely on maintaining enteral feeding when oral feeding is no longer possible or adequate with an emphasis on nutrition and quality of life (QOL). Previous publications have also alluded to potential benefits in medication adherence, for example, in children with HIV, renal disease and neurodisability. We describe a cohort of children with refractory epilepsy who refused oral medication and in whom PEG tube placement was initiated for the purpose of drug administration. DESIGN: We identified children from the medical records of two tertiary paediatric units over a 9-year period who had PEG tube placement for administration of antiepileptic drug (AED) therapy and collected demographic and clinical details from chart reviews. We assessed parent-reported changes in seizure control and QOL using a structured questionnaire. RESULTS: Ten patients met the inclusion criteria. All families reported an improvement in ease of administering medications and eight reported a significant improvement in QOL. Nine children had a decrease in seizure frequency (lasting more than 12 months) following PEG tube placement, including two who underwent surgical intervention for their epilepsy during that period. Four had either a decrease in the number of drugs administered or their doses and four went on to receive fluids and nutrition through their tube on a regular basis. Seven reported PEG complications, which did not require removal of the PEG. CONCLUSIONS: This case series of children with resistant epilepsy demonstrates improvement in seizure control and QOL following PEG tube placement for AED administration.

A recurrent mitochondrial p.Trp22Arg NDUFB3 variant causes a distinctive facial appearance, short stature and a mild biochemical and clinical phenotype.

BACKGROUND: Isolated Complex I deficiency is the most common paediatric mitochondrial disease presentation, associated with poor prognosis and high mortality. Complex I comprises 44 structural subunits with at least 10 ancillary proteins; mutations in 29 of these have so far been associated with mitochondrial disease but there are limited genotype-phenotype correlations to guide clinicians to the correct genetic diagnosis. METHODS: Patients were analysed by whole-exome sequencing, targeted capture or candidate gene sequencing. Clinical phenotyping of affected individuals was performed. RESULTS: We identified a cohort of 10 patients from 8 families (7 families are of unrelated Irish ancestry) all of whom have short stature (<9th centile) and similar facial features including a prominent forehead, smooth philtrum and deep-set eyes associated with a recurrent homozygous c.64T>C, p.Trp22Arg NDUFB3 variant. Two sibs presented with primary short stature without obvious metabolic dysfunction. Analysis of skeletal muscle from three patients confirmed a defect in Complex I assembly. CONCLUSIONS: Our report highlights that the long-term prognosis related to the p.Trp22Arg NDUFB3 mutation can be good, even for some patients presenting in acute metabolic crisis with evidence of an isolated Complex I deficiency in muscle. Recognition of the distinctive facial features-particularly when associated with markers of mitochondrial dysfunction and/or Irish ancestry-should suggest screening for the p.Trp22Arg NDUFB3 mutation to establish a genetic diagnosis, circumventing the requirement of muscle biopsy to direct genetic investigations.