Kabuki (Niikawa-Kuroki) syndrome associated with immunodeficiency

From Genotype to Phenotype-A Review of Kabuki Syndrome

Kabuki syndrome (KS) is a rare neuro-developmental disorder caused by variants in genes of histone modification, including KMT2D and KDM6A. This review assesses our current understanding of KS, which was originally named Niikawa-Kuroki syndrome, and aims to guide surveillance and medical care of affected individuals as well as identify gaps in knowledge and unmet patient needs. Ovid MEDLINE and EMBASE databases were searched from 1981 to 2021 to identify reports related to genotype and systems-based phenotype characterization of KS. A total of 2418 articles were retrieved, and 152 were included in this review, representing a total of 1369 individuals with KS. Genotype, phenotype, and the developmental and behavioral profile of KS are reviewed. There is a continuous clinical phenotype spectrum associated with KS with notable variability between affected individuals and an emerging genotype-phenotype correlation. The observed clinical variability may be attributable to differences in genotypes and/or unknown genetic and epigenetic factors. Clinical management is symptom oriented, fragmented, and lacks established clinical care standards. Additional research should focus on enhancing understanding of the burden of illness, the impact on quality of life, the adult phenotype, life expectancy and development of standard-of-care guidelines.

Clinical heterogeneity of Kabuki syndrome in a cohort of Italian patients and review of the literature

Kabuki syndrome (KS) is a well-recognized disorder characterized by postnatal growth deficiency, dysmorphic facial features, skeletal anomalies, and intellectual disability. The syndrome is caused by KMT2D gene mutations or less frequently KDM6A gene mutations or deletions. We report a systematic evaluation of KS patients from Campania region of Italy; data were also compared with literature ones. We collected data of 15 subjects (8 males and 7 females with age range 10-26 years; mean age 16.9 years) with confirmed diagnosis of KS, representing the entire cohort of patients from Campania Region. Each patient performed biochemical testing and instrumental investigation. Neuro-intellectual development, cranio-facial dysmorphisms, and multisystem involvement data were collected retrospectively. For each category, type of defects and frequency of the anomalies were analyzed. Our observation shows that KS patients from Campania region have some particular and previously underscored, neurological and immunological findings. We found high prevalence of EEG's abnormalities (43%) and MRI brain abnormalities (60%). Microcephaly resulted more common in our series (33%), if compared with major cohorts described in literature. Biochemical features of immunodeficiency and autoimmune diseases including thyroid autoimmunity, polyserositis, and vitiligo were observed with high prevalence (54.5%). Low immunoglobulins levels were a frequent finding. Lymphocyte class investigation showed significantly reduced CD8 levels in one patient.Conclusions: These data confirm great heterogeneity of clinical manifestations in KS and suggest to introduce further clinical diagnostic criteria in order to perform a correct and precocious diagnosis. What is Known • Kabuki syndrome is characterized by growth deficiency, dysmorphic facial features, skeletal anomalies, and intellectual disability • Immune dysfunction is a common finding but autoimmune diseases are rarely seen • Neurological features are common What is New • Some particular facial features could help gestalt diagnosis (hypertelorism, broad nasal bridge, micrognathia, tooth agenesis, cutaneous haemangiomas and strabismus) • Higher prevalence of autoimmune disorders than previously reported • Particular neurological features are present in this cohort (EEG and MRI brain abnormalities).

Kabuki Syndrome-Clinical Review with Molecular Aspects

Kabuki syndrome (KS) is a rare developmental disorder principally comprised of developmental delay, hypotonia and a clearly defined dysmorphism: elongation of the structures surrounding the eyes, a shortened and depressed nose, thinning of the upper lip and thickening of the lower lip, large and prominent ears, hypertrichosis and scoliosis. Other characteristics include poor physical growth, cardiac, gastrointestinal and renal anomalies as well as variable behavioral issues, including autistic features. De novo or inherited pathogenic/likely pathogenic variants in the KMT2D gene are the most common cause of KS and account for up to 75% of patients. Variants in KDM6A cause up to 5% of cases (X-linked dominant inheritance), while the etiology of about 20% of cases remains unknown. Current KS diagnostic criteria include hypotonia during infancy, developmental delay and/or intellectual disability, typical dysmorphism and confirmed pathogenic/likely pathogenic variant in KMT2D or KDM6A. Care for KS patients includes the control of physical and psychomotor development during childhood, rehabilitation and multi-specialist care. This paper reviews the current clinical knowledge, provides molecular and scientific links and sheds light on the treatment of Kabuki syndrome individuals.

SCID newborn screening: What we've learned

Newborn screening for severe combined immunodeficiency, the most profound form of primary immune system defects, has long been recognized as a measure that would decrease morbidity and improve outcomes by helping patients avoid devastating infections and receive prompt immune-restoring therapy. The T-cell receptor excision circle test, developed in 2005, proved to be successful in pilot studies starting in the period 2008 to 2010, and by 2019 all states in the United States had adopted versions of it in their public health programs. Introduction of newborn screening for severe combined immunodeficiency, the first immune disorder accepted for population-based screening, has drastically changed the presentation of this disorder while providing important lessons for public health programs, immunologists, and transplanters.

Reference intervals for lymphocyte subsets in preterm and term neonates without immune defects

BACKGROUND

In 6.5 years of newborn screening for severe combined immunodeficiency in California, 3,252,156 infants had DNA from dried blood spots (DBSs) assayed for T-cell receptor excision circles. Infants with T-cell receptor excision circle values of less than a designated cutoff on a single DBS, 2 DBS samples with insufficient PCR amplification, or known genetic risk of immunodeficiency had peripheral blood complete blood counts and lymphocyte subsets assayed in a single flow cytometry laboratory. Cases in which immune defects were ruled out were available for analysis.

OBJECTIVE

We sought to determine reference intervals for lymphocyte subsets in racially/ethnically diverse preterm and term newborns who proved to be unaffected by any T-lymphopenic immune disorder.

METHODS

Effective gestational age (GA) was defined as GA at birth plus postnatal age at the time of sample collection. After determining exclusion criteria, we analyzed demographic and clinical information, complete and differential white blood cell counts, and lymphocyte subsets for 301 infants, with serial measurements for 33 infants. Lymphocyte subset measurements included total T cells, helper and cytotoxic T-cell subsets, naive and memory phenotype of each T-cell subset, B cells, and natural killer cells.

RESULTS

Reference intervals were generated for absolute numbers and lymphocyte subsets from infants with effective GAs of 22 to 52 weeks. Sex and ethnicity were not significant determinants of lymphocyte subset counts in this population. Lymphocyte counts increased postnatally.

CONCLUSION

This study provides a baseline for interpreting comprehensive lymphocyte data in preterm and term infants, aiding clinicians to determine which newborns require further evaluations for immunodeficiency.

Epigenetic control of the immune system: a lesson from Kabuki syndrome

Kabuki syndrome (KS) is a rare multi-systemic disorder characterized by a distinct face, postnatal growth deficiency, mild-to-moderate intellectual disability, skeletal and visceral (mainly cardiovascular, renal, and skeletal) malformations, dermatoglyphic abnormalities. Its cause is related to mutations of two genes: KMT2D (histone-lysine N-methyltransferase 2D) and KDM6A (lysine-specific demethylase 6A), both functioning as epigenetic modulators through histone modifications in the course of embryogenesis and in several biological processes. Epigenetic regulation is defined as the complex of hereditable modifications to DNA and histone proteins that modulates gene expression in the absence of DNA nucleotide sequence changes. Different human disorders are caused by mutations of genes involved in the epigenetic regulation, and not surprisingly, all these share developmental defects, disturbed growth (in excess or defect), multiple congenital organ malformations, and also hematological and immunological defects. In particular, most KS patients show increased susceptibility to infections and have reduced serum immunoglobulin levels, while some suffer also from autoimmune manifestations, such as idiopathic thrombocytopenic purpura, hemolytic anemia, autoimmune thyroiditis, and vitiligo. Herein we review the immunological aspects of KS and propose a novel model to account for the immune dysfunction observed in this condition.

Kabuki syndrome: clinical and molecular characteristics

Kabuki syndrome (KS) is a rare syndrome characterized by multiple congenital anomalies and mental retardation. Other characteristics include a peculiar facial gestalt, short stature, skeletal and visceral abnormalities, cardiac anomalies, and immunological defects. Whole exome sequencing has uncovered the genetic basis of KS. Prior to 2013, there was no molecular genetic information about KS in Korean patients. More recently, direct Sanger sequencing and exome sequencing revealed KMT2D variants in 11 Korean patients and a KDM6A variant in one Korean patient. The high detection rate of KMT2D and KDM6A mutations (92.3%) is expected owing to the strict criteria used to establish a clinical diagnosis. Increased awareness and understanding of KS among clinicians is important for diagnosis and management of KS and for primary care of KS patients. Because mutation detection rates rely on the accuracy of the clinical diagnosis and the inclusion or exclusion of atypical cases, recognition of KS will facilitate the identification of novel mutations. A brief review of KS is provided, highlighting the clinical and genetic characteristics of patients with KS.

CHARGE syndrome: a review of the immunological aspects

CHARGE syndrome is caused by a dominant variant in the CHD7 gene. Multiple organ systems can be affected because of haploinsufficiency of CHD7 during embryonic development. CHARGE syndrome shares many clinical features with the 22q11.2 deletion syndrome. Immunological abnormalities have been described, but are generally given little attention in studies on CHARGE syndrome. However, structured information on immunological abnormalities in CHARGE patients is necessary to develop optimal guidelines for diagnosis, treatment and follow-up in these patients. Here, we provide an overview of the current literature on immunological abnormalities in CHARGE syndrome. We also explore immunological abnormalities in comparable multiple congenital anomaly syndromes to identify common immunological phenotypes and genetic pathways that might regulate the immune system. Finally, we aim to identify gaps in our knowledge on the immunological aspects in CHARGE syndrome that need further study.

Genetic syndromic immunodeficiencies with antibody defects

This article reviews the major syndromic immunodeficiencies with significant antibody defects, many of which may require intravenous immunogammaglobulin therapy. The authors define syndromic immunodeficiency as an illness associated with a characteristic group of phenotypic abnormalities or laboratory features that comprise a recognizable syndrome. Many are familial with a defined inheritance pattern. Immunodeficiency may not be a major part of the illness and may not be present in all patients; thus, these conditions differ from primary immunodeficiency syndromes, in which immune abnormalities are a consistent and prominent feature of their disease.

Kabuki syndrome with trichrome vitiligo, ectodermal defect and hypogammaglobulinemia A and G

We report a unique combination of symptoms in a case of Kabuki syndrome (KS), a multiple malformation/mental retardation syndrome that has a prevalence of 1:32,000 to 1:86,000. The patient was a mentally delayed 12-year-old male with trichrome vitiligo, ectodermal defect, and hypogammaglobulinemia A and G. This unique combination of signs, described here for the first time, indicates that KS comprises multiple deficits that affect not only the brain, but ectoderm-derived structures and the immune system as well. Our report may provide important clues for understanding the pathogenesis of the KS.

Cardiac conduction abnormalities and congenital immunodeficiency in a child with Kabuki syndrome: case report

Background

Since it's recognition in 1981, a more complete phenotype of Kabuki syndrome is becoming evident as additional cases are identified. Congenital heart defects and a number of visceral abnormalities have been added to the typical dysmorphic features originally described.

Case Report

In this report we describe the clinical course of a child diagnosed with Kabuki syndrome based on characteristic clinical, radiological and morphologic features who died of a cardiac arrhythmia at 11-months of age. This infant, however, had abnormal pulmonary architecture and alterations in his cardiac conduction system resulting in episodes of bradycardia and asystole. This child also had an immunological phenotype consistent with common variable immunodeficiency. His clinical course consisted of numerous hospitalizations for recurrent bacterial infections and congenital hypogammaglobulinemia characterized by low serum IgG and IgA but normal IgM levels, and decreased antibody levels to immunizations. T-, B- and NK lymphocyte subpopulations and T-cell function studies were normal.

Conclusion

This child may represent a more severe phenotype of Kabuki syndrome. Recurrent infections in a child should prompt a thorough immunological evaluation. Additionally, electrophysiology testing may be indicated if cardiopulmonary events occur which are not explained by anatomic defects.

Kabuki syndrome: a review

Kabuki syndrome (KS) (Kabuki make-up syndrome, Niikawa-Kuroki syndrome) is a multiple malformation/mental retardation syndrome that was described initially in Japan but is now known to occur in many other ethnic groups. It is characterized by distinctive facial features (eversion of the lower lateral eyelid, arched eyebrows with the lateral one-third dispersed or sparse, depressed nasal tip, and prominent ears), skeletal anomalies, dermatoglyphic abnormalities, short stature, and mental retardation. A number of other manifestations involving other organ systems can aid in the diagnosis and management of KS. This review will focus on the diagnostic criteria, the common and rare features of KS by organ system, and the possible etiology of this interesting condition.

Kabuki syndrome: new ocular findings but no evidence of 8p22-p23.1 duplications in a clinically defined cohort

The underlying cause of the multiple congenital anomalies/mental retardation syndrome Kabuki syndrome (KS, OMIM 147920) has not yet been established. We identified seven patients who fulfilled the classical clinical criteria for this syndrome and undertook a detailed clinical, ophthalomological and molecular cytogenetic review. Three of the seven patients had previously undetected ocular anomalies including myopia, ptosis, strabismus and tilted discs. The identification of preventable causes of loss of vision underlines the value of detailed ophthalmologic examination of KS patients. Using BAC fluorescence in situ hybridisation, there was no evidence of the duplication of 8p recently reported by Milunsky and Huang. We conclude that the cause of KS has yet to be established.

Further delineation of Kabuki syndrome in 48 well-defined new individuals

Kabuki syndrome is a multiple congenital anomaly/mental retardation syndrome. This study of Kabuki syndrome had two objectives. The first was to further describe the syndrome features. In order to do so, clinical geneticists were asked to submit cases-providing clinical photographs and completing a phenotype questionnaire for individuals in whom they felt the diagnosis of Kabuki syndrome was secure. All submitted cases were reviewed by four diagnosticians familiar with Kabuki syndrome. The diagnosis was agreed upon in 48 previously unpublished individuals. Our data on these 48 individuals show that Kabuki syndrome variably affects the development and function of many organ systems. The second objective of the study was to explore possible etiological clues found in our data and from review of the literature. We discuss advanced paternal age, cytogenetic abnormalities, and familial cases, and explore syndromes with potentially informative overlapping features. We find support for a genetic etiology, with a probable autosomal dominant mode of inheritance, and speculate that there is involvement of the interferon regulatory factor 6 (IRF6) gene pathway. Very recently, a microduplication of 8p has been described in multiple affected individuals, the proportion of individuals with the duplication is yet to be determined.

Immune abnormalities are a frequent manifestation of Kabuki syndrome

Kabuki syndrome (KS) is associated with multiple organ system involvement. Characteristic features include long palpebral fissures with everted lower lids, prominent ears, skeletal abnormalities, mental retardation, and short stature. An increased incidence of infection has been reported in KS, and a few patients have been noted to have immune defects. However, the frequency and severity of the immune deficiency has not been clearly defined. Immunologic evaluation of 19 consecutive individuals with KS was performed at The Children's Hospital of Philadelphia. Decreased IgA levels were noted in 15/19 individuals (79%), 2 of whom had undetectable levels. Eight patients (42%) also had low total IgG levels. Specific IgG subclass abnormalities were found in 6 of 13 patients evaluated. IgM levels were less frequently decreased. One patient failed to generate anti-tetanus antibodies despite immunization. This study suggests that hypogammaglobulinemia is a frequent finding in children with KS. The pattern of antibody abnormalities seen in children with KS resembles common variable immune deficiency (CVID). Due to this increased susceptibility to infection, children with KS should have immunologic evaluations at the time of diagnosis in order to reduce preventable morbidity and mortality.

Kabuki syndrome: Clinical data in 20 patients, literature review, and further guidelines for preventive management

The Kabuki syndrome, or Niikawa-Kuroki syndrome, is a clinically recognizable syndrome of unknown etiology. Clinical findings include early hypotonia, joint laxity, developmental delay, facial dysmorphism, persistent fetal fingertip pads, cleft palate, hypodontia, lip nodules, heart defects, and a variety of other structural defects. Behavior in general is social and pleasant. In collaboration with the Dutch Kabuki Network, we evaluated the medical data of 20 individuals diagnosed with the syndrome and compared them with data from the literature. In our literature review we used convincing cases only. Frequent findings in the oral region are under-reported in the literature: apart from the cleft palate (in about 50%), hypodontia with predominantly absence of the upper lateral incisors, and a full lower lip with symmetrical nodules, or (in a minority) lip-pits are frequent findings. Also under-reported is the presence of a thickened nuchal fold during pregnancy and hydrops in the neonatal period. Clinical recognition in the neonate is difficult. Towards early puberty acute and serious weight excess has been experienced. We suggest that a cytogenetic abnormality should be ruled out in all cases. We provide further guidelines for preventive management.

Syndromic immunodeficiencies: genetic syndromes associated with immune abnormalities

In syndromic immunodeficiencies, clinical features not directly associated with the immune defect are prominent. Patients may present with either infectious complications or extra-immune medical issues. In addition to the immunologic abnormality, a wide range of organ systems may be affected. Patients may present with disturbances in skeletal, neurologic, dermatologic, or gastrointestinal function or development. These conditions can be caused by developmental abnormalities, chromosomal aberrations, metabolic disorders, or teratogens. For a number of these conditions, recent advances have resulted in an enhanced understanding of their genetic basis. The finding of immune deficits in a number of defined syndromes with congenital anomalies suggests that an underlying genetic syndrome should be considered in those patients in whom a significant non-immune feature is present.

Patient with Kabuki syndrome and acute leukemia

Kabuki syndrome is a multiple congenital anomaly/mental retardation syndrome which often involves recurrent infections. There is cumulative evidence of an immunodeficiency in Kabuki patients. We report a 2-year-old girl with typical Kabuki syndrome, who developed acute lymphocytic leukemia. The patient showed low levels of immunoglobulins G and A and a history of recurrent infections, that might indicate an immunodeficiency leading to an increased susceptibility to cancer. The girl was treated according to BFM protocols adapted to the patient's impaired cardiac situation and severe underweight. She achieved continual complete remission. Classical and molecular cytogenetic analyzes did not detect any abnormality.

A case showing an association between type 1 diabetes mellitus and Kabuki syndrome

The case of a 31-year-old female suffering from type 1 diabetes mellitus (DM) and Kabuki syndrome is presented. The patient was diagnosed as having impaired glucose tolerance (IGT) at age 18; secondary amenorrhea occurred at age 20, following acute body weight loss. Extensive examination revealed the patient to have a slowly progressive form of type 1 DM and, based on the physical findings, including her facial features, she was diagnosed as also having congenital Kabuki syndrome. Since then, this patient has experienced several episodes of diabetic ketoacidosis, all of which were brought about by prolonged bronchial infection. Although it is perhaps reasonable at present to consider this case to represent a chance association, further clinical investigations will be carried out to clarify whether or not Kabuki syndrome and type 1 DM have any common pathogenic features.

Kabuki make-up syndrome: a review

Kabuki make-up syndrome (KMS, OMIM 147920) is an MCA/MR syndrome of unknown cause. It is characterized by a dysmorphic face, postnatal growth retardation, skeletal abnormalities, mental retardation, and unusual dermatoglyphic patterns. Approximately more than 350 cases have been reported from all over the world. Besides these five cardinal manifestations, joint laxity (74%), dental abnormalities (68%), and susceptibility to infections including recurrent otitis media (63%) were well recognized as other frequent features. A variety of visceral anomalies such as cardiovascular anomalies (42%), renal and/or urinary tract anomalies (28%), biliary atresia, diaphragmatic hernia, and anorectal anomaly were also reported. Some patients were said to have normal intelligence (16%) and normal heights, suggesting that they may have reproductive fitness to have their children. At least eight patients had lower lip pits with or without cleft palate, known as a feature of van der Woude syndrome. There have been 13 chromosomal abnormalities associated with KMS. However, no common abnormalities or breakpoints that possibly contribute to positional cloning of the putative KMS gene(s) are known. Although clinical manifestations of KMS are well established, its natural history, useful for genetic counseling, remains to be studied.

Kabuki syndrome: a review study of three hundred patients

The Kabuki (make-up) syndrome identified in 1981 has been reported in more than three hundred patients. Typical findings include mild to moderate mental retardation, fetal pads, cleft palate, and characteristic facies with long palpebral fissures, everted lower lateral eyelids and arched eyebrows. Postnatal growth retardation, skeletal and visceral anomalies are present in a large percentage of patients. We review here the characteristics of this peculiar syndrome in three hundred patients.

Phenotypic spectrum and management issues in Kabuki syndrome

OBJECTIVE

To report the phenotypic spectrum and management issues of children with Kabuki syndrome (Niikawa-Kuroki syndrome) from North America.

DESIGN

A case series of children (n = 18) with clinical findings of Kabuki syndrome.

SETTING

Medical genetics clinics in Washington, Alaska, and Arizona.

RESULTS

Most patients had postnatal growth retardation, and all had developmental delay and hypotonia. Feeding difficulties, with or without cleft palate, were common; 5 patients required gastrostomy tube placement. Developmental quotients/IQs in all but 2 were 60 or less. Seizures were seen in less than half of the patients, but ophthalmologic and otologic problems were common, particularly recurrent otitis media. Congenital heart defects were present in 7 (39%); 3 patients underwent repair of coarctation of the aorta. Other features included urinary tract anomalies, malabsorption, joint hypermobility and dislocation, congenital hypothyroidism, idiopathic thrombocytopenic purpura, and in one patient, autoimmune hemolytic anemia and hypogammaglobulinemia. All patients had negative family histories for Kabuki syndrome.

CONCLUSIONS

Kabuki syndrome is a mental retardation-malformation syndrome affecting multiple organ systems, with a broad spectrum of neuromuscular dysfunction and mental ability. Given that 18 ethnically diverse patients were identified from 2 genetics programs, it appears that this syndrome is more common in North American non-Japanese patients than previously appreciated.