Speech characteristics in the Kabuki syndrome

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.

Characteristics and surgical outcomes of cleft palate in kabuki syndrome: a case series of 11 patients

OBJECTIVE

A significant number of patients with KS have cleft palate (CP) or submucous cleft palate (SMCP) and show delayed speech development. However, few reports have discussed the characteristics of CP in KS and the outcomes of postoperative speech development. The purpose of this study was to investigate the characteristics and surgical outcomes of CP in patients with KS, and to discuss the importance of the diagnosis of CP or SMCP.

METHODS

We conducted a retrospective study on patients with clinically diagnosed KS who underwent palatoplasty. Clinical and surgical data were collected from patients' medical records, and velopharyngeal function was evaluated using nasopharyngoscopy and speech analysis.

RESULTS

In 11 cases, 5 patients had CP (45.5%) and 6 had SMCP (54.5%). Four patients who were genetically tested had a pathogenic variant of KMT2D. Seven of nine patients (77.8%) who underwent conventional palatoplasty showed velopharyngeal insufficiency and hypernasality. All patients who underwent pharyngeal flap surgery achieved velopharyngeal competency. Statistical analysis revealed a statistically significant difference in postoperative results between non-syndromic and KS patients.

CONCLUSION

Patients with SMCP may be more common than previously reported. The results showed that it is difficult to produce optimal results with conventional palatoplasty; therefore, pharyngeal flap surgery should be considered as a treatment to obtain favorable results. Pharyngeal flap surgery in patients with KS should be carefully designed based on speech evaluation and nasopharyngoscopic findings.

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.

KMT2C/D COMPASS complex-associated diseases [KCDCOM-ADs]: an emerging class of congenital regulopathies

The type 2 lysine methyltransferases KMT2C and KMT2D are large, enzymatically active scaffold proteins that form the core of nuclear regulatory structures known as KMT2C/D COMPASS complexes (complex of proteins associating with Set1). These evolutionarily conserved proteins regulate DNA promoter and enhancer elements, modulating the activity of diverse cell types critical for embryonic morphogenesis, central nervous system development, and post-natal survival. KMT2C/D COMPASS complexes and their binding partners enhance active gene expression of specific loci via the targeted modification of histone-3 tail residues, in general promoting active euchromatic conformations. Over the last 20 years, mutations in five key COMPASS complex genes have been linked to three human congenital syndromes: Kabuki syndrome (type 1 [KMT2D] and 2 [KDM6A]), Rubinstein-Taybi syndrome (type 1 [CBP] and 2 [EP300]), and Kleefstra syndrome type 2 (KMT2C). Here, we review the composition and biochemical function of the KMT2 complexes. The specific cellular and embryonic roles of the KMT2C/D COMPASS complex are highlight with a focus on clinically relevant mechanisms sensitive to haploinsufficiency. The phenotypic similarities and differences between the members of this new family of disorders are outlined and emerging therapeutic strategies are detailed.

Neurobehavioral features in individuals with Kabuki syndrome

Background

Kabuki syndrome (KS) is a disorder characterized by multiple congenital anomalies affecting development and function of multiple systems. Over the years, researchers have attempted to characterize the neurobehavioral phenotype of KS in cohorts of patients enrolled on the basis of clinical assessment. The availability of molecular testing now allows for recruitment of patients with confirmed KS due to KMT2D and KDM6A.

Methods

The aims of the present study were to investigate the neuropsychological and behavioral profiles of individuals with molecularly confirmed diagnosis of KS, and determine the extent of heterogeneity occurring in these profiles between individuals with clinical diagnosis of KS with and without mutations in KMT2D. We also described performance of our cohort in any neuropsychological domain investigated.

Results

We documented a marked variation in the neuropsychological profile of subjects with clinical diagnosis of KS, even though a relatively homogeneous impairment in linguistic domains and motor skills was observed. No significant difference occurred between mutation‐positive and mutation‐negative groups. Phonological disorders and oromotor dysfunctions were also found, and adaptive functioning was characterized by low performance in daily living and in motor domain.

Conclusion

The present study allowed identification of a distinctive neurobehavioral profile in a cohort of individuals affected by KS with or without molecularly confirmed diagnosis. These findings are expected to help clinicians define more accurately targeted protocols for individualized intervention.

Cleft Palate in Kabuki Syndrome: A Report of Six Cases

Kabuki syndrome is a syndrome of rare congenital anomalies that was named after its characteristic appearance, a face resembling that of an actor in a Kabuki play. Although cleft palate is a feature that is sometimes observed in patients with Kabuki syndrome, there are few clinical reports of cleft palate associated with Kabuki syndrome. This report presents six cases of Kabuki syndrome with cleft palate and reviews their clinical features. Our results suggest that (1) patients with cleft palate in Kabuki syndrome tend to fail in acquiring normal velopharyngeal function and (2) submucous cleft palate might be more common in patients with Kabuki syndrome than previously was reported.

A 35-year experience with syndromic cleft palate repair: operative outcomes and long-term speech function

BACKGROUND

Associated comorbidities can put syndromic patients with cleft palate at risk for poor speech outcomes. Reported rates of velopharyngeal insufficiency (VPI) vary from 8% to 64%, and need for secondary VPI surgery from 23% to 64%, with few studies providing long-term follow-up. The purpose of this study was to describe our institutional long-term experience with syndromic patients undergoing cleft palatoplasty.

METHODS

A retrospective review was conducted of all patients with syndromic diagnoses undergoing primary Furlow palatoplasty from 1975 to 2011. Outcomes included postoperative oronasal fistula (ONF) and need for secondary VPI surgery. Speech scores for verbal patients 5 years or older were collected via the Pittsburgh scale for speech assessment. Aggregate scores categorized the velopharyngeal mechanism as competent, borderline, or incompetent. Outcomes were analyzed by patient and operative factors.

RESULTS

One hundred thirty-two patients were included with average age at repair of 20.7 months. Cleft type was 9% submucosal, 16% Veau class I, 50% class II, 12% class III, and 13% class IV. Forty-five syndromes were recorded, most commonly Stickler syndrome (n = 32) and 22q11.2 deletion syndrome [22q11.2DS (n = 19)]. Forty-four patients also had associated Pierre Robin sequence (PRS). The overall ONF rate was 4.5% and was highest in Veau class IV clefts (P = 0.048). Seventy-six patients were included in speech analysis, with an average age at last assessment of 10.4 years. Overall, 60.5% of patients had a competent velopharyngeal mechanism, 23.7% borderline, and 15.8% incompetent mechanism. Fifty percent of 22q11.2DS patients had borderline speech and none had competent speech, compared to 73.3% with Stickler syndrome (P = 0.01) and 71.4% of patients with associated PRS (P = 0.02). Secondary VPI surgery was performed in 11.4% of patients overall. Patients with PRS (13.6%) and with Stickler syndrome (15.6%) had secondary VPI surgery, compared to 31.6% of patients with 22q11.2DS (P = 0.01).

CONCLUSIONS

This study demonstrates low rates of postoperative ONF after modified Furlow palatoplasty in syndromic patients. Speech outcomes were comparable to nonsyndromic patients at our institution, but patients with 22q11.2DS consistently had borderline-incompetent speech and a 3-fold higher incidence of secondary VPI surgery.

Evaluation for language and speech development in Kabuki make-up syndrome: a case report

Kabuki make-up syndrome (KMS) is defined as a rare syndrome with mental retardation, growth deficiency and multiple anomalies of unknown cause. Cases have a characteristic facial appearance of broad and low auricles, wide forehead, broad and flattened nose root. In this article, 4-year, 10-month-old boy with speech delay reported due to characteristics of the facial appearance is considered as KMS, a rare syndrome. Otological, audiological and developmental evaluation of the patient consisted of six parameters. (1) ENT examination: normal. (2) Audiological findings were at normal hearing levels. (3) General development (according to the Denver II test), was normal. (4) Language and speech development: receptive language development was 2 years more than the chronological age. However in expressive language development, there was 5-month delay which was likely to complete by training in a short time. (5) The development of speech sounds and articulation: the delay is observed in CVC words. Speech sounds of /l/, /t/, /r/ and /g/ were evaluated as "distorted expression". He used /v/ instead of /l/; /y/ instead of /r/; /d/ instead of /g/. (6) OBSERVATIONS: diffident, deficit in self-confidence, and difficulty in communicating have been observed.Unlike the cases in literature, mental retardation, growth deficiency and learning difficulties were not found in our case with KMS. Normal findings were obtained in five parameters. Only the /l/, /r/ and /g/ speech sounds were expressed as distorted. For our case, we planned to follow him in the future to see whether developmental and central auditory processing disorders will occur or not.

Dental findings in Kabuki make-up syndrome: a case report

This article documents the case history of a 9-year-old Brazilian child diagnosed with Kabuki make-up syndrome (KMS). The clinical features are described, with emphasis on the craniofacial and orodental manifestations. The patient had the distinctive KMS craniofacial features consisting of long palpebral fissure, hypertelorism, high-arched eyebrows with sparse hair in the lateral one-third, eyes with eversion of the lateral one-third of the lower eyelids, long and curved eyelashes, palpebral ptosis, large anteverted prominent ears in a lower position, broad, depressed nasal root with a flat nasal tip, and mild neuropsychomotor developmental deficits. The intraoral examination revealed an anterior open bite, overretention of primary teeth, and a high-arched palate. Two findings in this child have not been previously reported in patients with KMS: the presence of supernumerary teeth and taurodontic teeth in the maxillary arch. The clinical and radiographic detection of these unique dental features may be helpful in identifying children who may have milder forms of KMS.

Characteristics of Movement of the Lips, Tongue and Velum during a Bilabial Plosive

Objective: To obtain dynamic images of articulators using a magnetic resonance imaging (MRI) movie and to clarify the relationships among the articulators.

Materials and Methods: The subjects consisted of 10 volunteers. Custom-made circuitry was connected to an MRI apparatus to enable an external trigger pulse to control the timing of the scanning sequence and to provide an auditory cue for synchronization of the subject's utterance. The subject repeated a bilabial plosive, and the run was measured using a gradient echo sequence with a repetition time of 30 ms. Several variables were defined to delineate the individual movements of articulators and to determine the temporal relationships among them.

Results: It was found that (1) the change in these variables showed distinctive waveforms; (2) mean values of the standard deviations for these variables were relatively small; and (3) the movement of the velum was significantly correlated with those of the lips and the anterior part of the tongue, but not with the posterior part of the tongue.

Conclusions: These results suggest that (1) articulatory movements were clearly recorded using an MRI movie, and (2) there seems to be a central mechanism for controlling articulators, and the level of coupling may be associated with the place of articulation.

Kabuki syndrome: oral and general features seen in a 2-year-old Chinese boy

This report describes the case of a young Chinese boy with Kabuki syndrome (KS). KS is a congenital condition characterized by multiple anomalies, especially of the face, and is usually associated with mild to moderate mental retardation. The patient presented with the characteristic facial features of KS and some skeletal and neurological anomalies including a butterfly vertebrae with scoliosis, cerebral atrophy, and irregular dentition. Dental examination revealed screwdriver-shaped incisors and a high arched maxilla, features typical of patients with KS, as well as very poor oral hygiene and early childhood caries. This report includes discussion of the aetiology of KS as well as discussion of the long-term prognosis for this particular patient, and patients with KS in general, with consideration of associated dental and medical issues.

Kabuki make-up (Niikawa-Kuroki) syndrome: dental and craniofacial findings in a Brazilian child

This article reports the case of a Brazilian child diagnosed with Kabuki make-up syndrome (KMS), addressing the clinical features observed, with emphasis on the disease-specific oral and craniofacial manifestations. The patient had the distinctive KMS craniofacial appearance, mild delayed mental development, fingers with prominent fingertip pads and visual deficit. The dental findings included fusion of the left mandibular incisors (central and lateral), gemination of the right mandibular central incisor and congenital agenesis of the right mandibular lateral incisor, in the primary dentition, as well as absence of both permanent mandibular lateral incisors. Fusion and gemination have not been previously referred to as typical dental features in KMS. The detection of unique dental findings, such as missing teeth and dental anomalies of form in the primary dentition by means of clinical and radiographic examinations, might consist of a helpful diagnosis parameter in identifying children who may have milder forms of Kabuki syndrome.

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.

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.

Expressive language in children with Kabuki syndrome

Since the description of Kabuki syndrome in 1981 over 300 cases from a variety of countries have been reported. Only a limited number of these reports, however, provided data on speech language development. Ghent University Hospital (J. Van Borsel, T. Defloor) and the Department of Clinical Genetics, Academic Hospital Maastricht (C.T.R.M. Schrander-Stumpel, L.M.G. Curfs) are directing research on the specific nature of communicative development in persons with Kabuki syndrome. The aim of the present study was to delineate the language difficulties in the syndrome. The subjects were six Dutch-speaking children (three male, three female), with chronological age ranging from 4.4 to 10.6 years (mean = 8.1). Spontaneous speech samples were collected, subjected to a consensus orthographic transcription, and analyzed by means of TOAST [Moerman-Coetsier and Van Besien, 1987], a Dutch standardized diagnostic instrument to investigate different aspects of spontaneous language production. In all the children, expressive language abilities were impaired. Poor morphosyntactic abilities were consistently demonstrated. Lexical and pragmatic difficulties were also present, whereas phonological development was less often affected.

Intellectual abilities and adaptive behavior of children and adolescents with Kabuki syndrome: A preliminary study

Very little is known about the intellectual abilities and adaptive behavior of individuals who have Kabuki syndrome, beyond the fact that most individuals with this syndrome have mental retardation. To fill this gap, we have completed psychological assessments of 11 children and adolescents with Kabuki syndrome. Results indicated that most of the participants functioned in the range of mild mental retardation, with both intellectual and adaptive behavior in the mildly deficient range and problem behaviors, if any, limited to mild difficulties with inattention and/or hyperactivity-impulsivity and mild problems with obsession/anxiety. At the lower extreme, one child evidenced severe mental retardation and profound adaptive behavior impairment accompanied by serious externalizing and internalizing problem behaviors. At the upper extreme, one adolescent had average intelligence and adaptive behavior, with problem behaviors well within the normal range for his chronological age. Most participants evidenced relative intellectual strengths in verbal and reasoning abilities and a relative weakness in visuospatial construction abilities. This pattern affected adaptive behavior as well, yielding a relative strength in Social Interaction and Communicative Skills and considerable weakness in Motor Skills and Personal Living Skills.