Isolated adrenocorticotropin deficiency in a child with Kabuki syndrome

Hypoglycemia and Dandy-Walker variant in a Kabuki syndrome patient: a case report

Background

Kabuki syndrome (KS) is a rare congenital condition with cardinal manifestations of typical facial features, developmental delays, skeletal anomalies, abnormal dermatoglyphic presentations, and mild to moderate intellectual disability. Pathogenic variants in two epigenetic modifier genes, KMT2D and KDM6A, are responsible for KS1 and KS2, respectively.

Case presentation

A Chinese girl had persistent neonatal hypoglycemia and Dandy-Walker variant. Whole-exome sequencing identified a novel single nucleotide deletion in KMT2D (NM_003482.3 c.12165del p.(Glu4056Serfs*10)) that caused frameshift and premature termination. The mutation was de novo. According to the American College of Medical Genetics and Genomics (ACMG) guidelines, this variant is considered pathogenic. The patient was diagnosed with KS by molecular testing.

Conclusion

A single novel mutation in KMT2D was identified in a KS patients with hypoglycemia and Dandy-Walker variant in the neonatal stage. A molecular test was conducted to diagnose KS at an early stage.

Congenital hyperinsulinism as the presenting feature of Kabuki syndrome: clinical and molecular characterization of 9 affected individuals

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.

Identification of novel KMT2D mutations in two Chinese children with Kabuki syndrome: a case report and systematic literature review

Background

Kabuki syndrome (KS) is a rare pediatric congenital disorder with multiple congenital anomalies and intellectual disabilities, which is inherited in an autosomal dominant manner. Mutations in KMT2D and KDM6A have been proven to be the primary cause in most cases of KS.

Case presentation

Here we report two Chinese boys with clinical features of KS referred to our hospital for clinical diagnosis. Next-generation sequencing was performed on MiSeq to analyze the genetic mutations in both patients. In both, two novel de novo mutations in KMT2D gene (c.5235delA, p.(A1746Lfs*39) and c.7048G > A, p.(Q2350*)) were detected, both of which were subsequently confirmed by the two-generation pedigree analysis based on Sanger sequencing. A systematic literature review of previously reported mutational spectrum of KMT2D was also conducted.

Conclusions

Two novel de novo mutations in KMT2D gene were identified and considered to be pathogenic in both of KS patients. Our data adds information to the growing knowledge on the mutational spectrum of KS.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0545-5) contains supplementary material, which is available to authorized users.

Persistent Hyperinsulinism in Kabuki Syndrome 2: Case Report and Literature Review

Kabuki syndrome is a clinically and genetically heterogeneous congenital malformation syndrome with protean clinical manifestations. This reflects the important epigenetic role in embryonic development of the two genes currently known to be associated with Kabuki syndrome i.e., KMT2D and KDM6A, which are responsible for Kabuki syndrome 1 and Kabuki syndrome 2, respectively. Hypoglycemia is thought to be a rare manifestation of Kabuki syndrome; however it may be under diagnosed. Herein we describe the case of a 5-year-old girl with Kabuki syndrome 2 in whom persistent hyperinsulinism was diagnosed at 4 years of age. We postulate an epigenetic mechanism for hyperinsulinism where specific loss KDM6A demethylation of the H3K27me3/me2 mark may lead to deregulated pancreatic ß-cell development.

De novo exonic deletion of KDM6A in a Chinese girl with Kabuki syndrome: A case report and brief literature review

Kabuki syndrome (KS) is a rare condition with multiple congenital anomalies and mental retardation. Exonic deletions, disrupting the lysine (K)-specific demethylase 6A (KDM6A) gene have been demonstrated as rare cause of KS. Here, we report a de novo 227-kb deletion in chromosome Xp11.3 of a 7-year-old Chinese girl with KS. Besides the symptoms of KS, the patient also presented with skin allergic manifestations, which were considered to be a new, rare feature of the phenotypic spectrum. The deletion includes the upstream region and exons 1-2 of KDM6A and potentially causes haploinsuffiency of the gene. We also discuss the mutation spectrum of KDM6A and clinical variability of patients with KDM6A deletion through a literature review. © 2016 Wiley Periodicals, Inc.

Kabuki syndrome: a Chinese case series and systematic review of the spectrum of mutations

Background

Kabuki syndrome is a rare hereditary disease affecting multiple organs. The causative genes identified to date are KMT2D and KDMA6. The aim of this study is to evaluate the clinical manifestations and the spectrum of mutations of KMT2D.

Methods

We retrospectively retrieved a series of eight patients from two hospitals in China and conducted Sanger sequencing for all of the patients and their parents if available. We also reviewed the literature and plotted the mutation spectrum of KMT2D.

Results

The patients generally presented with typical clinical manifestations as previously reported in other countries. Uncommon symptoms included spinal bifida and Dandy-Walker malformation. With respect to the mutations, five mutations were found in five patients, including two frameshift indels, one nonsense mutation and two missense mutations.

Conclusions

This is the first case series on Kabuki syndrome in Mainland China. Unusual symptoms, such as spinal bifida and Dandy-Walker syndrome, suggested that neurological developmental defects may accompany Kabuki syndrome. This case series helps broaden the mutation spectrum of Kabuki syndrome and adds information regarding the manifestations of Kabuki syndrome.

Hypoglycemia in Kabuki syndrome

Kabuki syndrome (KS) is a congenital malformation disorder with a spectrum of clinical manifestations involving different organs. Until the identification of MLL2 gene mutation in 2010, the diagnosis was made only clinically by the characteristic facial features with other common and uncommon features. Hypoglycemia, although an uncommon feature in KS, is very important to be recognized, as early diagnosis and appropriate management will reduce further long-term neurologic morbidity in these patients. We report on four patients with KS presenting with persistent hypoglycemia. Hyperinsulinemic hypoglycemia was the cause of hypoglycemia in two out of four patients and one patient had growth hormone deficiency. The mechanism of the hypoglycemia in one patient is still unclear. Three out of these four patients were found to have mutation in the MLL2 gene. Our observations suggest that patients with KS may have hypoglycemia due to different mechanisms and that MLL2 gene may have a role in glucose physiology.

Infrequent Manifestations of Kabuki Syndrome in a Patient with Novel MLL2 Mutation

We present a case of a 9-month-old Hispanic female with Kabuki syndrome with some infrequent manifestations including a single umbilical artery, butterfly vertebrae, a small larynx, a preauricular pit, microtia with internal ear abnormalities, abnormal calcium metabolism, premature thelarche, neonatal/persistent hypoglycemia and eventration of the diaphragm. She was found to have a previously unreported nonsense MLL2 mutation. This is the first case that includes all such findings occurring simultaneously that was genotyped.

Severe Hypoglycemia due to Isolated ACTH Deficiency in Children: A New Case Report and Review of the Literature

Isolated ACTH deficiency causes life-threatening severe hypoglycemia. A 7-year-old girl with hypoglycemia due to this rare disorder is described. Our patient had undetectable plasma ACTH repeatedly and cortisol 0 mcg/dl before and after ACTH 1-24 stimulation. There was no evidence of other pituitary hormone deficiency. Glucocorticoid replacement therapy resulted in resolution of all symptoms and normalization of blood glucose. Previously published data on isolated ACTH deficiency in children is summarized. Review of the literature showed that the prevalence of this condition could be underestimated in the neonatal period and in Prader-Willi syndrome. Isolated ACTH deficiency occurs in older children as well as in neonates.