Alpers-Huttenlocher Syndrome First Presented with Hepatic Failure: Can Liver Transplantation Be Considered as Treatment Option?

Living donor liver transplantation for myocerebrohepatopathy spectrum due to POLG mutations

BACKGROUND

POLG is one of several nuclear genes associated with mitochondrial DNA maintenance defects and is a group of diseases caused by mitochondrial DNA deficiency that results in impaired adenosine triphosphate production and organ dysfunction. Myocerebrohepatopathy spectrum (MCHS) is the most severe and earliest presentation of POLG mutations, and liver transplantation (LT) for MCHS has never been reported.

CASE PRESENTATION

The patient was a 3-month-old boy with acute liver failure and no neurological manifestations (e.g., seizures). We performed a living donor LT using a left lateral segment graft from his father. The postoperative course was uneventful. Subsequently, a homozygous POLG mutation (c.2890C>T, p. R964C) was identified by multigene analysis of neonatal/infantile intrahepatic cholestasis. Moreover, respiratory chain complex I, II, and III enzyme activities and the ratio of mtDNA to nuclear DNA in the liver were reduced. Therefore, we considered that these clinical manifestations and examination findings met the definition for MCHS. During meticulous follow-up, the patient had shown satisfactory physical growth and mental development until the time of writing this report.

CONCLUSION

We presumed that the absence of remarkable neurologic manifestations prior to LT in patients with MCHS is a good indication for LT and contributes to a better prognosis in the present case.

Clinical Attributes and Electroencephalogram Analysis of Patients With Varying Alpers' Syndrome Genotypes

Alpers' syndrome is an early inceptive neurodegenerative disorder with a poor prognosis, characterized by developmental regression, intractable epilepsy, and hepatic dysfunction. Candidate genes, such as POLG, PARS2, CARS2, FARS2, NARS2, and GABRB2 are distinguished and registered following research on large cohorts that portray the clinical phenotype in such patients using expanded access to whole-exome sequencing (WES). In this study, we aimed to better understand the electroencephalogram (EEG) characteristics and clinical phenotype of different genotypes of the Alpers' syndrome, which are currently insufficiently studied. We conducted a study on seven patients with Alpers' syndrome who received treatment in Beijing Children's Hospital and had a detailed clinical EEG. Furthermore, a substantial literature search of the Chinese Biomedical Literature Database, PubMed, and Cochrane Central Register of Controlled Trials EMBASE was also conducted, which revealed a total of 22 reported cases between January 2008 to January 2021. We analyzed 29 cases of Alpers' syndrome caused by different gene variants, of which 22 cases were related to POLG gene mutation and 7 cases were related to PARS2, CARS2, FARS2, NARS2, and GABRB2 gene mutation, and found that patients with distinctive pathogenic variants exhibited comparable phenotypes and similar EEG patterns. And we defined EEG characteristics found specifically in Alpers' syndrome. Rhythmic high-amplitude delta with superimposed (poly) spikes (RHADS) is a characteristic EEG finding in the early stages of Alpers' syndrome and is a kind of epileptic phenomenon, which can provide clues for the early diagnosis of the disease.

The Perirolandic Sign: A Unique Imaging Finding Observed in Association with Polymerase γ-Related Disorders

Pathogenic variants in the polymerase γ gene (POLG) cause a diverse group of pathologies known as POLG-related disorders. In this report, we describe brain MR imaging findings and electroencephalogram correlates of 13 children with POLG-related disorders at diagnosis and follow-up. At diagnosis, all patients had seizures and 12 had abnormal MR imaging findings. The most common imaging findings were unilateral or bilateral perirolandic (54%) and unilateral or bilateral thalamic signal changes (77%). Association of epilepsia partialis continua with perirolandic and thalamic signal changes was present in 86% and 70% of the patients, respectively. The occipital lobe was affected in 2 patients. On follow-up, 92% of the patients had disease progression or fatal outcome. Rapid volume loss was seen in 77% of the patients. The occipital lobe (61%) and thalamus (61%) were the most affected brain regions. Perirolandic signal changes and seizures may represent a brain imaging biomarker of early-onset pediatric POLG-related disorders.