A Rare Cause of Hyperinsulinemic Hypoglycemia: Kabuki Syndrome

Persistent Hypoglycemia and Hyperinsulinism in a Patient With KMT2D-Associated Kabuki Syndrome

We report a 3-year-old girl with persistent hypoglycemia and hyperinsulinism secondary to KMT2D-associated Kabuki syndrome (KS). During the neonatal period, the patient had multiple complications, including gastroesophageal reflux disease, failure to thrive, G-tube dependence, congenital heart disease, and persistent hypoglycemia. The initial workup at 2 weeks of age was suggestive of hyperinsulinism. She was treated with intravenous glucose infusion and diazoxide. She was discharged from the NICU on diazoxide, chlorothiazide, and enteral feeds. Diazoxide was discontinued at 2 months old secondary to adverse effects. Hyperinsulinemic hypoglycemia was ultimately confirmed with a glucagon stimulation test at 5 months of age. At 11 months of age, when the enteral feeds were attempted to be spaced, she presented to our outpatient clinic with persistent hypoglycemia. Review of prior outside records confirmed a negative congenital hyperinsulinism genetic panel. She was treated with maltodextrin, enteral feeds, and close glucose monitoring. We noted that she had dysmorphic features that were suggestive of KS. At 2 years of age, a whole exome sequence confirmed a pathogenic mutation in KMT2D. Persistent hypoglycemia beyond the neonatal period is a rare finding in KS. In addition, it is a more common finding in KS type 2 (KDM6A).

Syndromic forms of congenital hyperinsulinism

Congenital hyperinsulinism (CHI), also called hyperinsulinemic hypoglycemia (HH), is a very heterogeneous condition and represents the most common cause of severe and persistent hypoglycemia in infancy and childhood. The majority of cases in which a genetic cause can be identified have monogenic defects affecting pancreatic β-cells and their glucose-sensing system that regulates insulin secretion. However, CHI/HH has also been observed in a variety of syndromic disorders. The major categories of syndromes that have been found to be associated with CHI include overgrowth syndromes (e.g. Beckwith-Wiedemann and Sotos syndromes), chromosomal and monogenic developmental syndromes with postnatal growth failure (e.g. Turner, Kabuki, and Costello syndromes), congenital disorders of glycosylation, and syndromic channelopathies (e.g. Timothy syndrome). This article reviews syndromic conditions that have been asserted by the literature to be associated with CHI. We assess the evidence of the association, as well as the prevalence of CHI, its possible pathophysiology and its natural course in the respective conditions. In many of the CHI-associated syndromic conditions, the mechanism of dysregulation of glucose-sensing and insulin secretion is not completely understood and not directly related to known CHI genes. Moreover, in most of those syndromes the association seems to be inconsistent and the metabolic disturbance is transient. However, since neonatal hypoglycemia is an early sign of possible compromise in the newborn, which requires immediate diagnostic efforts and intervention, this symptom may be the first to bring a patient to medical attention. As a consequence, HH in a newborn or infant with associated congenital anomalies or additional medical issues remains a differential diagnostic challenge and may require a broad genetic workup.

[Congenital hyperinsulinism as a part of Kabuki syndrome]

Kabuki syndrome is a rare hereditary disease characterized by distinctive facial features, skeletal abnormalities, mental retardation, developmental delay, and anomalies in multiple organ systems development.Congenital hyperinsulinism is a rare manifestation of his Kabuki syndrome. However, early diagnosis is crucial to prevent neurological complications of hypoglycemia.There are 2 types of Kabuki Syndrome depending on severity of symptoms. Kabuki syndrome Type 1 is associated with heterozygous mutations in gene KMT2D. Kabuki syndrome Type 2 is inherited in an X-linked manner. It's associated with heterozygous mutations in gene KDM6A and characterized by more severe course of the disease.This paper presents 2 cases of children with congenital hyperinsulinism as the feature of Kabuki syndrome Type 1 and Type 2.

Using deep-neural-network-driven facial recognition to identify distinct Kabuki syndrome 1 and 2 gestalt

Kabuki syndrome (KS) is a rare genetic disorder caused by mutations in two major genes, KMT2D and KDM6A, that are responsible for Kabuki syndrome 1 (KS1, OMIM147920) and Kabuki syndrome 2 (KS2, OMIM300867), respectively. We lack a description of clinical signs to distinguish KS1 and KS2. We used facial morphology analysis to detect any facial morphological differences between the two KS types. We used a facial-recognition algorithm to explore any facial morphologic differences between the two types of KS. We compared several image series of KS1 and KS2 individuals, then compared images of those of Caucasian origin only (12 individuals for each gene) because this was the main ethnicity in this series. We also collected 32 images from the literature to amass a large series. We externally validated results obtained by the algorithm with evaluations by trained clinical geneticists using the same set of pictures. Use of the algorithm revealed a statistically significant difference between each group for our series of images, demonstrating a different facial morphotype between KS1 and KS2 individuals (mean area under the receiver operating characteristic curve = 0.85 [p = 0.027] between KS1 and KS2). The algorithm was better at discriminating between the two types of KS with images from our series than those from the literature (p = 0.0007). Clinical geneticists trained to distinguished KS1 and KS2 significantly recognised a unique facial morphotype, which validated algorithm findings (p = 1.6e-11). Our deep-neural-network-driven facial-recognition algorithm can reveal specific composite gestalt images for KS1 and KS2 individuals.