De novo variants of IRF2BPL result in developmental epileptic disorder.

BACKGROUND: Pathogenic variants of the IRF2BPL gene have been reported to cause neurodevelopmental disorders; however, studies focused on IRF2BPL in zebrafish are limited. RESULTS: We reported three probands diagnosed with developmental delay and epilepsy and investigated the role of IRF2BPL in neurodevelopmental disorders in zebrafish. The clinical and genetic characteristics of three patients with neurodevelopmental disorder with regression, abnormal movements, loss of speech and seizures (NEDAMSS) were collected. Three de novo variants (NM_024496.4: c.1171 C > T, p.Arg391Cys; c.1157 C > T, p.Thr386Met; and c.273_307del, p.Ala92Thrfs*29) were detected and classified as pathogenic or likely pathogenic according to ACMG guidelines. Zebrafish crispants with disruption of the ortholog gene irf2bpl demonstrated a reduced body length and spontaneous ictal-like and interictal-like discharges in an electrophysiology study. After their spasms were controlled, they gain some development improvements. CONCLUSION: We contribute two new pathogenic variants for IRF2BPL related developmental epileptic disorder which provided evidences for genetic counseling. In zebrafish model, we for the first time confirm that disruption of irf2bpl could introduce spontaneous electrographic seizures which mimics key phenotypes in human patients. Our follow-up results suggest that timely cessation of spasmodic seizures can improve the patient's neurodevelopment.

[Clinical and genetic analysis of two pedigrees affected with aromatic L-amino acid decarboxylase deficiency].

OBJECTIVE: To delineate the clinical and genetic features of two pedigrees affected with aromatic L-amino acid decarboxylase (AADC) deficiency. METHODS: The clinical features, family history and results of genetic testing of 2 patients with AADC deficiency were retrospectively analyzed. RESULTS: Both patients featured hypotension, developmental delay and oculogyric crisis during infancy. Genetic testing confirmed that they have respectively carried c.714+ 4 (IVS6) A to T/c.175(exon2)G TO A compound heterozygous variants and c.714+ 4(IVS6)A to T homozygous variant. CONCLUSION: The clinical manifestation of children with AADC deficiency may include hypotonia, developmental delay and paroxysmal oculogyric crisis. The combination of 3-O-methyldopa testing and variant analysis is not only very useful for early diagnosis, but also important for the evaluation of treatment effect and prognosis of the disease. Discovery of the novel variants has enriched the variant spectrum of AADC deficiency.