New ocular findings in a case of Kabuki syndrome

Macular dystrophy in Kabuki syndrome due to de novo KMT2D variants: refining the phenotype with multimodal imaging and follow-up over 10 years: insight into pathophysiology

BACKGROUND

Kabuki Syndrome is a rare and genetically heterogenous condition with both ophthalmic and systemic complications and typical facial features. We detail the macular phenotype in two unrelated patients with Kabuki syndrome due to de novo nonsense variants in KMT2D, one novel. A follow-up of 10 years is reported. Pathogenicity of both de novo nonsense variants is analyzed.

METHODS

Four eyes of two young patients were studied by full clinical examination, kinetic perimetry, short wavelength autofluorescence, full field (ff) ERGs, and spectral-domain optical coherence tomography (SD-OCT). One patient had adaptive optic (AO) imaging. Whole exome sequencing was performed in both patients.

RESULTS

Both patients had de novo nonsense variants in KMTD2. One patient had c.14843C>G; p. (Ser4948ter) novel variant and the second c.11119C>T; p. (Arg3707ter). Both had a stable Snellen visual acuity of 0.2-0.3. The retinal multimodal imaging demonstrated abnormalities at the fovea in both eyes: hyperreflectivity to blue light and a well-delimited gap-disruption of ellipsoid and interdigitation layer on OCT. The dark area on AO imaging is presumed to be absent for, or with structural change to photoreceptors. The ff ERGs and kinetic visual fields were normal. The foveal findings remained stable over several years.

CONCLUSION

Kabuki syndrome-related maculopathy is a distinct loss of photoreceptors at the fovea as shown by multimodal imaging including, for the first time, AO imaging. This report adds to the literature of only one case with maculopathy with two additional macular dystrophies in patients with Kabuki syndrome. Although underestimated, these cases further raise awareness of the potential impact of retinal manifestations of Kabuki syndrome not only among ophthalmologists but also other healthcare professionals involved in the care of patients with this multisystem disorder.

Ophthalmic manifestations in Kabuki (make-up) syndrome: A single-center pediatric cohort and systematic review of the literature

Kabuki syndrome (KS) is a genetic disorder caused by pathogenic variants in KMT2D or KDM6A, and manifesting with multi-systemic involvement, including recognizable facial features, developmental delay and multiple congenital anomalies. Ophthalmological involvement has been described in varying rates in several studies. We aimed to evaluate the prevalence and nature of ophthalmological findings in a cohort of KS patients in Israel. Medical records of all patients diagnosed with KS in our tertiary center between 2004 and 2020 were retrospectively reviewed. Data collected included physical examination findings, molecular analysis as well as comprehensive ophthalmic characteristics including visual acuity, ocular alignment and motility, ocular adnexa, anterior segments and dilated fundus exams. Finally, an updated systematic review of the literature was performed. Thirteen unrelated patients were included in the study, diagnosed at an age raging from the first months of life to 20 years. Of these, three (23%) showed significant ophthalmological abnormalities, beyond the characteristic structural findings of long palpebral fissures and lower eyelid eversion. These included bilateral posterior colobomata in the first patient; bilateral ptosis, hypermetropia, esotropia, blue sclera and anisocoria in the second; and bilateral congenital cataracts in the third. To conclude, our findings underscore the importance of a comprehensive ophthalmological evaluation as part of the routine multidisciplinary assessment of children suspected/diagnosed with KS.

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.

Congenital Refractory Glaucoma: A New Ophthalmic Association of Kabuki Syndrome and its Management With Glaucoma Drainage Devices

INTRODUCTION

Kabuki syndrome (KS) is a rare congenital and polymalformative condition, traditionally associated with mental retardation, unusual facial features, and skeletal abnormalities. We hereby describe a case of bilateral congenital glaucoma associated with MLL2-mutation KS. To the best of our knowledge, this is the first association of KS with congenital glaucoma.

CASE REPORT

The patient was a 3-year-old male of North African ethnicity diagnosed with KS and bilateral congenital glaucoma at the age of 3 months and the first child of a nonconsanguineous healthy couple, with no known genetic conditions within the family. The patient was referred to our tertiary glaucoma center with uncontrollable intraocular pressures between 50 and 60 mm Hg in both eyes. Past ophthalmic history included bilateral trabeculectomies and right retinal detachment with phthisis bulbi. We performed left lensectomy combined with Baerveldt tube insertion in the vitreous cavity, revealing extensive posterior synechiae. Postoperatively, he developed intense inflammation with fibrin and vitreous strand formation, requiring subsequent surgeries and subconjunctival injections of betamethasone. Despite these complications, IOP stabilized between 3 and 6 mm Hg.

DISCUSSION

This case confirms congenital glaucoma as a rare association of KS, and highlights the potential high-risk nature of such cases. In our opinion, the presence of high levels of inflammation perioperatively and postoperatively is an indication for primary glaucoma drainage device surgery given the high risk of bleb scarring resulting in recurrent surgical revisions. In view of these observations, we also advocate the use of intensive postoperative anti-inflammatory therapy.

Salzmann nodular degeneration features in a case of Kabuki make-up syndrome

Kabuki syndrome (KS) is a multiple congenital anomaly syndrome with diversified ophthalmological manifestations. We report a case of a boy with bilateral features of Salzmann nodular degeneration (SND) associated with KS. An 18-year-old Caucasian man with KS presented for a second opinion regarding incapacitating photophobia in his right eye, refractory to medical therapy. Biomicroscopy revealed bilateral subepithelial nodules in the midperiphery of the cornea, less extensive in the left eye, consistent with SND. Symptomatic improvement was achieved after superficial keratectomy, manually performed with a blade and adjuvant application of mitomycin C. We report a rare case of a KS patient with SND. Since KS manifestations may vary widely, it is important to perform an early ophthalmological examination for prompt detection and treatment of ocular abnormalities and thus improve life quality in these patients.

Kabuki syndrome: expanding the phenotype to include microphthalmia and anophthalmia

Kabuki syndrome is a rare genetic malformation syndrome that is characterized by distinct facies, structural defects and intellectual disability. Kabuki syndrome may be caused by mutations in one of two histone methyltransferase genes: KMT2D and KDM6A. We describe a male child of nonconsanguineous Irish parents presenting with multiple malformations, including bilateral extreme microphthalmia; cleft palate; congenital diaphragmatic hernia; duplex kidney; as well as facial features of Kabuki syndrome, including interrupted eyebrows and lower lid ectropion. A de-novo germline mutation in KMT2D was identified. Whole-exome sequencing failed to reveal mutations in any of the known microphthalmia/anopthalmia genes. We also identified four other patients with Kabuki syndrome and microphthalmia. We postulate that Kabuki syndrome may produce this type of ocular phenotype as a result of extensive interaction between KMT2D, WAR complex proteins and PAXIP1. Children presenting with microphthalmia/anophthalmia should be examined closely for other signs of Kabuki syndrome, especially at an age where the facial gestalt might be less readily appreciable.

Rare ocular features in a case of Kabuki syndrome (Niikawa-Kuroki syndrome)

BACKGROUND

Kabuki syndrome is a multi-system disorder with peculiar facial features, and ophthalmic abnormalities are frequently involved. This case report of a child with Kabuki syndrome describes two new previously unreported ophthalmic conditions.

CASE PRESENTATION

A 3-year-old Taiwanese boy with Kabuki syndrome had a short stature, spinal dysraphism, intellectual disability and typical facial features. Ophthalmic findings which have been previously reported in the literature and in this patient, included ptosis, esotropia, coloboma of the iris, retina, choroid and optic disc, and microcornea. The newly identified ophthalmic features in this patient included colobomatous microphthalmos and a dysplastic and elevated disc without central cupping. The genetic analysis identified an MLL2 gene mutation.

CONCLUSION

The presentations of a dysplastic disc and colobomatous microphthalmia are rarely reported in patients with Kabuki syndrome, but these ophthalmic abnormalities may affect vision. Detailed ophthalmic evaluations in children with Kabuki syndrome are advised.

Ocular manifestations in Kabuki syndrome: the first report from Saudi Arabia

BACKGROUND

Kabuki syndrome (KS) is a multiple congenital anomaly syndrome in which ophthalmological examination for the early detection of ocular abnormalities is desired in order to prevent visual impairment.

CASE

Retrospective, interventional, case report of a 5-year-old female patient of Arabic origin with features of Kabuki syndrome.

OBSERVATION

Patient had neurological deficit, psychomotor retardation, a peculiar face, including large prominent cup shaped ears, broad depressed nasal tip, and high arched palate, and malformed teeth. Her ocular features suggestive of Kabuki syndrome included left upper eyelid congenital ptosis, lagophthalmos, arched eyebrows with temporal sparing of hair, long horizontal palpebral fissures, lateral lower eyelid eversion and resultant epiphora. Other abnormalities included medial lower epicanthal folds, abduction deficit bilaterally, large esotropia, significant hyperopia, right corneal opacity, iris and chorioretinal coloboma. Patient required hyperopic correction and ptosis surgery, which improved her visual functioning.

CONCLUSIONS

We report the first case of a Kabuki syndrome patient from Saudi Arabia and stress on the importance of ophthalmological examination in all patients with KS for the early detection of ocular anomalies in order to prevent visual impairment.