A Case of MIRAGE Syndrome with Mutation and Refractory Infantile Diarrhea: Endoscopic Biopsy Evaluation via Light and Electron Microscopy.

An infant with intrauterine growth restriction, suspected of having MIRAGE syndrome based on prenatal ultrasound, presented with genital ambiguity, adrenal insufficiency, intractable diarrhea from birth, and a pathogenic mutation (). Endoscopic biopsies of the duodenum revealed complex light and electron microscopic abnormalities. Hypoplastic villi without signs of enteritis suggests a disorder of mucosal growth with reduced absorptive surface area contributes to intractable diarrhea.

Homozygous missense variants in YKT6 result in loss of function and are associated with developmental delay, with or without severe infantile liver disease and risk for hepatocellular carcinoma.

Purpose: YKT6 plays important roles in multiple intracellular vesicle trafficking events but has not been associated with Mendelian diseases.

Methods: We report 3 unrelated individuals with rare homozygous missense variants in YKT6 who exhibited neurological disease with or without a progressive infantile liver disease. We modeled the variants in Drosophila.

Intrahepatic Cholangiolitis in Cystic Fibrosis (ICCF): An Under-Appreciated Cause of Persistent Cholestasis in Infancy.

Liver histology in infants with cystic fibrosis (CF) and persistent cholestasis is seldom reported in detail. We extend previous observation of a distinctive intrahepatic cholangiopathy (ICCF) to 3 additional infants homozygous for pathological variants and a fourth infant with a heterozygous variant, summarizing our experience in 10 infants with variants and persistent cholestasis. Cholangiograms demonstrate abnormal extrahepatic ducts in 2 infants with CF, 1 with uniform dilatation interpreted as a choledochal cyst and the other with narrow patent ducts.

Clinical spectrum and genetic causes of mitochondrial hepatopathy phenotype in children.

Background: Alterations in both mitochondrial DNA (mtDNA) and nuclear DNA genes affect mitochondria function, causing a range of liver-based conditions termed mitochondrial hepatopathies (MH), which are subcategorized as mtDNA depletion, RNA translation, mtDNA deletion, and enzymatic disorders. We aim to enhance the understanding of pathogenesis and natural history of MH.

Methods: We analyzed data from patients with MH phenotypes to identify genetic causes, characterize the spectrum of clinical presentation, and determine outcomes.

A novel RYR1 variant in an infant with a unique fetal presentation of central core disease.

Ryanodine receptor type 1-related disorder (RYR1-RD) is the most common subgroup of congenital myopathies with a wide phenotypic spectrum ranging from mild hypotonia to lethal fetal akinesia. Genetic testing for myopathies is imperative as the diagnosis informs counseling regarding prognosis and recurrence risk, treatment options, monitoring, and clinical management. However, diagnostic challenges exist as current options are limited to clinical suspicion prompting testing including: single gene sequencing or familial variant testing, multi-gene panels, exome, genome sequencing, and invasive testing including muscle biopsy.