ABSTRACT
PURPOSE: Describe the clinical and molecular findings of patients with Kabuki syndrome (KS) who present with hypoglycemia due to congenital hyperinsulinism (HI), and assess the incidence of KS in patients with HI. METHODS: We documented the clinical features and molecular diagnoses of 9 infants with persistent HI and KS via a combination of sequencing and copy-number profiling methodologies. Subsequently, we retrospectively evaluated 100 infants with HI lacking a genetic diagnosis, for causative variants in KS genes. RESULTS: Molecular diagnoses of KS were established by identification of pathogenic variants in KMT2D (n = 5) and KDM6A (n = 4). Among the 100 infants with HI of unknown genetic etiology, a KS diagnosis was uncovered in one patient. CONCLUSIONS: The incidence of HI among patients with KS may be higher than previously reported, and KS may account for as much as 1% of patients diagnosed with HI. As the recognition of dysmorphic features associated with KS is challenging in the neonatal period, we propose KS should be considered in the differential diagnosis of HI. Since HI in patients with KS is well managed medically, a timely recognition of hyperinsulinemic episodes will improve outcomes, and prevent aggravation of the preexisting mild to moderate intellectual disability in KS.
Subject(s)
Abnormalities, Multiple/genetics , Congenital Hyperinsulinism/genetics , DNA-Binding Proteins/genetics , Face/abnormalities , Hematologic Diseases/genetics , Histone Demethylases/genetics , Neoplasm Proteins/genetics , Nuclear Proteins/genetics , Vestibular Diseases/genetics , Abnormalities, Multiple/diagnosis , Abnormalities, Multiple/physiopathology , Child, Preschool , Congenital Hyperinsulinism/complications , Congenital Hyperinsulinism/diagnosis , Congenital Hyperinsulinism/physiopathology , Face/physiopathology , Female , Genetic Predisposition to Disease , Hematologic Diseases/complications , Hematologic Diseases/diagnosis , Hematologic Diseases/physiopathology , Humans , Infant , Intellectual Disability/complications , Intellectual Disability/diagnosis , Intellectual Disability/genetics , Intellectual Disability/physiopathology , Male , Mutation , Pathology, Molecular , Retrospective Studies , Vestibular Diseases/complications , Vestibular Diseases/diagnosis , Vestibular Diseases/physiopathologyABSTRACT
The author Diva D. De Leon was incorrectly listed as instead of Diva D. De Leó-Critchlow in the original version of this paper.
ABSTRACT
Cornelia de Lange syndrome (CdLS) is a rare neurodevelopmental syndrome for which mutations in five causative genes that encode (SMC1A, SMC3, RAD21) or regulate (NIPBL, HDAC8) the cohesin complex, account for ~70% of cases. Herein we report on four female Subjects who were found to carry novel intragenic deletions in HDAC8. In one case, the deletion was found in mosaic state and it was determined to be present in ~38% of blood lymphocytes and in nearly all cells of a buccal sample. All deletions, for which parental blood samples were available, were shown to have arisen de novo. X-chromosome inactivation studies demonstrated marked skewing, suggesting strong selection against the mutated HDAC8 allele. Based on an investigation of the deletion breakpoints, we hypothesize that microhomology-mediated replicative mechanisms may be implicated in the formation of some of these rearrangements. This study broadens the mutational spectrum of HDAC8, provides the first description of a causative HDAC8 somatic mutation and increases the knowledge on possible mutational mechanisms underlying copy number variations in HDAC8. Moreover our findings highlight the clinical utility of considering copy number analysis in HDAC8 as well as the analysis on DNA from more than one tissue as an indispensable part of the routine molecular diagnosis of individuals with CdLS or CdLS-overlapping features.