Inheritance in Kabuki make-up (Niikawa-Kuroki) syndrome

Reprogramming of the epigenome in neurodevelopmental disorders

The etiology of neurodevelopmental disorders (NDDs) remains a challenge for researchers. Human brain development is tightly regulated and sensitive to cellular alterations caused by endogenous or exogenous factors. Intriguingly, the surge of clinical sequencing studies has revealed that many of these disorders are monogenic and monoallelic. Notably, chromatin regulation has emerged as highly dysregulated in NDDs, with many syndromes demonstrating phenotypic overlap, such as intellectual disabilities, with one another. Here we discuss epigenetic writers, erasers, readers, remodelers, and even histones mutated in NDD patients, predicted to affect gene regulation. Moreover, this review focuses on disorders associated with mutations in enzymes involved in histone acetylation and methylation, and it highlights syndromes involving chromatin remodeling complexes. Finally, we explore recently discovered histone germline mutations and their pathogenic outcome on neurological function. Epigenetic regulators are mutated at every level of chromatin organization. Throughout this review, we discuss mechanistic investigations, as well as various animal and iPSC models of these disorders and their usefulness in determining pathomechanism and potential therapeutics. Understanding the mechanism of these mutations will illuminate common pathways between disorders. Ultimately, classifying these disorders based on their effects on the epigenome will not only aid in prognosis in patients but will aid in understanding the role of epigenetic machinery throughout neurodevelopment.

Analysis of MLL2 gene in the first Brazilian family with Kabuki syndrome

Most patients with Kabuki syndrome (KS) are the only person in their family with the condition. However, familial cases of KS have been described showing evidence that this syndrome can be inherited as a dominant trait with variable expressivity. We report on two related individuals with facial findings characteristic of KS. The proposita had arched eyebrows, long and upward slanting palpebral fissures, cleft lip and palate, retromicrognathia, brachydactyly of hands and feet, stubby fingers, nail hypoplasia, and prominent finger pads. Her mother had eyebrows with dispersed lateral half, long and upward slanting palpebral fissures, retrognathia, abnormal and posteriorly rotated ears, prominent finger pads, brachydactyly of feet, learning difficulties, and psychomotor development delay. DNA sequencing revealed a novel missense mutation in the MLL2 gene in both the proposita and her mother. The mutation (p.R5432Q) was found in the exon 51, within the SET domain of the gene, which confers methyltransferase activity on the protein. Therefore, the epigenetic and transcriptional regulatory properties of this protein may be altered and this suggests that the mutation is the cause of phenotype observed in both the patient and her mother. The clinical signs and the molecular evidence in this family further support the notion that KS is an autosomal dominant condition with variable expressivity. To our knowledge this is the first report of a Brazilian family with recurrence of this syndrome.

Craniofacial and dental features in kabuki syndrome patients

Objective : To describe oral manifestations in Brazilian individuals with Kabuki syndrome, a multiple congenital anomaly/mental retardation syndrome. Study Design : A total of 16 Kabuki syndrome individuals, aged between 8 to 24 years and of both sexes, were referred by the Department of Clinical Genetics for oral treatment and follow-up to the Oral Care Center for Inherited Diseases, University Hospital of Brasília, Brasília, Brazil. Each individual underwent complete physical examination, as well as intraoral and radiographic examinations. Results : Craniofacial and dental alterations were observed in all Kabuki syndrome patients examined. In addition, atypical shape of the molars' crowns, occlusal convergence of the premolars' crowns, and root dilaceration were also observed. Enamel diffuse opacities were observed in permanent dentition (n  =  10). Conclusion : A great clinical heterogeneity was observed in Kabuki syndrome individuals in line with previous studies in the literature. Further clinical and molecular studies are necessary in order to better understand the presence of dental anomalies in this syndrome.

Seizures and EEG pattern in Kabuki syndrome

PURPOSE

Kabuki syndrome (KS) is a rare dysmorphogenic disorder that is characterized by multiple congenital abnormalities with central nervous system involvement. The diagnosis is clinical and a variable degree of mental retardation is always present. Epilepsy is frequently reported, but a typical electroclinical pattern has not been described. We describe the electroclinical features of eight KS non-Japanese patients with epilepsy.

METHODS

We analysed seizure characteristics and pattern EEG and clinical outcomes in eight KS patients.

RESULTS

All patients presented with focal seizures. A frontal epileptic status was present in two cases. We highlighted the fact that, during evolution, seven patients shared the same interictal EEG pattern, which was characterized by isolated or repetitive biphasic spikes or sharp waves, followed by a slow wave of medium and high voltage, predominantly localised in the fronto-central regions. The natural course of seizures is favourable.

CONCLUSIONS

Our results showed a peculiar homogeneous electroclinical pattern in KS, characterized by focal seizures more frequently origin in fronto-central area which demonstrated that seizures are mostly focal in type and that a fronto-central origin is more frequently evident.

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: 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.

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: report of six Thai children and further phenotypic and genetic delineation

We describe six Thai children with the Kabuki syndrome. Monozygotic twin boys discordant for the syndrome were encountered in a family. The affected twin had all five cardinal features of the syndrome, whereas the unaffected twin had none of them. The presence of monozygotic twins discordant for the syndrome argues against a single gene origin of the disorder, but by no means excludes it. In another family, a mother had a facial appearance similar to her affected son. Lower lip pits with or without symmetrical lower lip nodules were present in three of the six children, and pilonidal sinus was seen in five children. These clinical manifestations were much more common than previously described. Other inconsistent findings included early eruption of the lower central incisors, a skin defect of the head, and transient hyperthyrotropinemia in infancy.

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.

Kabuki syndrome-like features associated with a small ring chromosome X and XIST gene expression

Although clinical features in Kabuki syndrome (KS; Niikawa-Kuroki syndrome) have been well defined, the underlying genetic mechanism still remains unclear. We report a 9-year-old girl with typical KS-like facial appearance, skeletal and dermatoglyphic abnormalities, severe mental retardation, and growth deficiency. In 60 of 100 GTG-banded metaphases from peripheral blood lymphocytes, a ring chromosome smaller than a G group chromosome was found, which, according to reverse painting, consisted of Xq11.1q13. The proband's karyotype was described as mos45,X/46,X,+r(X). Several loci were analyzed with fluorescence in situ hybridization (FISH) and microsatellite markers revealing that one r(X) breakpoint mapped proximal to DXS422 (Xp11.21) and the second mapped distal to XIST gene, between loci DXS128E and DXS441 (Xq13.2). Uniparental disomy for X and r(X) was excluded and the paternal origin of r(X) was identified. XIST expression was demonstrated by nested reverse transcription polymerase chain reaction (RT-PCR) using primers spanning exons 5, 6i, and 6 in RNA prepared from lymphocytes. The observation of XIST expression is in contrast to two other cases in which the XIST gene was either not present on r(X) or not expressed. To our knowledge, this is the first case of Kabuki-like syndrome manifestations with r(X) and XIST expression.

Congenital heart defects in Kabuki syndrome

Kabuki makeup (Niikawa-Kuroki) syndrome (KS) is characterized by distinct facial anomalies, mental retardation, congenital heart defect (CHD), and skeletal malformations. In the present study we analyze cardiac characteristics and differences in sex prevalence of specific CHDs in our series of patients with KS and review published reports from the literature. Between January 1992 and February 2000, 60 patients (37 males and 23 females) with KS underwent phenotypic and cardiac evaluations at our hospital. CHD was diagnosed in 35 (58%) of our patients. Aortic coarctation (COA) (23%), atrial septal defect (ASD) (20%), and ventricular septal defect (VSD) (17%) were the most frequent CHDs in our series and in previous reports from the literature. Male preponderance was noted in patients with COA. In conclusion, CHD is a cardinal feature of KS. There is an overlap between cardiac malformations of KS and those of Turner syndrome. Male preponderance in patients with KS and COA supports the hypothesis that genes located on the X chromosome may be involved in determining KS in some patients. The high prevalence of CHD prompts accurate re-examination of patients evaluated by pediatric cardiologists in order to identify mild and still unrecognized cases of KS.

Further evidence for autosomal dominant inheritance and ectodermal abnormalities in Kabuki syndrome

Most cases with Kabuki syndrome (KS) were reported sporadically. Recently, a few familial cases of KS were reported. This report provides further evidence that the KS is inherited as a dominant trait with variable expressivity. The proposita is an 18-month-old girl with facial findings characteristic of Kabuki syndrome, prominent fingertip-pads, a midsagittal cleft of vertebral body D4, hypotonia, and psychomotor retardation. Her mother had a similar facial appearance, prominent, cup-shaped ears, an abnormal dentition, early breast development, and low-normal intelligence. Because mother and daughter both had evident Kabuki syndrome, we conclude that KS in this family is inherited as a dominant trait. Further family history supports this finding. Microscopic examination of the hair of the proposita shows abnormalities consisting of trichorrhexis nodosa, twisting of the hairshafts, and irregularity of the diameter of the hair, as was described recently in a patient with KS. This could be another occasional finding in this syndrome, but further studies are required. The presence of abnormal hair, nails, and the commonly described tooth abnormalities in KS further suggest ectodermal involvement in this syndrome.

Kabuki make-up syndrome is not caused by microdeletion close to the van der Woude syndrome critical region at 1q32-q41

We reported on a 5-year-old Japanese girl with clinical manifestations of Kabuki make-up syndrome (KMS) and van der Woude syndrome (VWS). Since the concurrence of the two syndromes is known in four patients, including ours, it suggests a common cause. Assuming that the association of the two syndromes was caused by a microdeletion involving the putative KMS/VWS genes, we carried out fluorescence in situ hybridization and microsatellite analyses using PAC clones and dinucleotide repeat markers spanning the VWS1 critical region at 1q32-q41. No deletion was detected at the VWS1 critical region.

Kabuki syndrome: description of dental findings in 8 patients

The cardinal features of Kabuki (Niikawa-Kuroki) syndrome (KS) include characteristic facial dysmorphic features, mild to moderate mental deficiency, skeletal abnormalities, dermatoglyphic abnormalities, and postnatal growth retardation. We identified 8 patients with KS in a genetics clinic over the past 5 years. All were Caucasians, except for 2 who were of mixed Aboriginal and Caucasian descent. All had the facial gestalt, the dermatoglyphic abnormalities characteristic of the syndrome, and developmental delay. Dental abnormalities of permanent teeth were seen in all 8 cases; 6 had missing lower incisors. Five patients had uniquely abnormal upper incisor teeth shape; the upper incisors had a 'flat head' screwdriver-shaped appearance. Other dental abnormalities included missing lower lateral incisors, missing second premolars, and ectopic upper 6-year molars. We believe the presence of the unique dental findings will prove useful in the diagnostic assessment of individuals with KS.

Epilepsy and polymicrogyria in Kabuki make-up (Niikawa-Kuroki) syndrome

Kabuki make-up syndrome is a rare dysmorphogenic disorder characterized by peculiar facial appearance (resembling the make-up of actors in Kabuki, the traditional Japanese theatre), skeletal anomalies, dermatoglyphic abnormalities, postnatal growth deficiency, and mental retardation. Central nervous system dysfunctions, other than mental retardation, are rarely reported; they include microcephaly, brachycephaly, early hypotonia, feeding disorders, subatrophy of the optic nerves, subarachnoid cyst, cerebellar and brainstem atrophy, and epilepsy. These manifestations appear to be more common in non-Japanese patients. Reported is an Italian child with phenotypical appearance of Kabuki make-up syndrome and partial epilepsy who demonstrated polymicrogyria on neuroimaging. This article is the first report of a gyration disorder in Kabuki make-up syndrome. The relationship between epilepsy and polymicrogyria in this patient is discussed.

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.

Thirteen cases of Niikawa-Kuroki syndrome: report and review with emphasis on medical complications and preventive management

Eight new and five previously illustrated patients with Niikawa-Kuroki syndrome (NKS) are compared to those in the literature, providing data on 183 cases. Eight patients had disproportionate microcephaly and in one autopsied patient there was frontal lobe atrophy, focal polymicrogyria, and a hypoplastic fourth ventricle. The metacarpophalangeal pattern profiles of three Caucasian patients with NKS were similar to that of a prior case report, but those of two Hispanic patients were more variable. NKS was eliminated by follow-up in nine suspect cases, highlighting the diagnostic value of findings such as arched eyebrows, long palpebral fissures, flat nasal tip, and prominent finger pads. One patient suspected of having NKS had a very different metacarpophalangeal pattern profile, supporting its diagnostic utility in selected cases. Higher frequencies of neonatal complications, abnormal dentition, hypotonia, and microcephaly were noted in non-Asian patients with NKS, while a higher frequency of skeletal anomalies was seen in Japanese patients. Complications affecting cognitive, visual, hearing, cardiac, renal, skeletal, immune, and endocrinologic functions are translated into a program for preventive management. X chromosome anomalies are the most compelling of diverse genetic changes seen in NKS, and this report adds another case to several possible instances of vertical transmission. The 108 non-Asian patients now reported emphasize the worldwide significance of NKS recognition.

Ectodermal abnormalities in Kabuki syndrome

We describe a girl with Niikawa-Kuroki (Kabuki) syndrome (NKS) with conical incisors, hypodontia, hypoplastic nails, and brittle hair. Abnormal teeth are common in NKS and support a hypothesis of autosomal dominant inheritance of the syndrome [Halal et al., 1989; Silengo et al., 1996]. Hair abnormalities have never been investigated in NKS. The ectodermal involvement in NKS could represent an important clue for the understanding of the pathogenesis of this syndrome.