Kabuki syndrome is a congenital anomaly syndrome characterized by developmental delay, intellectual disability, specific facial features including long palpebral fissures and ectropion of the lateral third of the lower eyelids, prominent digit pads, and skeletal and visceral abnormalities. Mutations in MLL2 and KDM6A cause Kabuki syndrome. We screened 81 individuals with Kabuki syndrome for mutations in these genes by conventional methods (n = 58) and/or targeted resequencing (n = 45) or whole exome sequencing (n = 5). We identified a mutation in MLL2 or KDM6A in 50 (61.7%) and 5 (6.2%) cases, respectively. Thirty-five MLL2 mutations and two KDM6A mutations were novel. Non-protein truncating-type MLL2 mutations were mainly located around functional domains, while truncating-type mutations were scattered through the entire coding region. The facial features of patients in the MLL2 truncating-type mutation group were typical based on those of the 10 originally reported patients with Kabuki syndrome; those of the other groups were less typical. High arched eyebrows, short fifth finger, and hypotonia in infancy were more frequent in the MLL2 mutation group than in the KDM6A mutation group. Short stature and postnatal growth retardation were observed in all individuals with KDM6A mutations, but in only half of the group with MLL2 mutations.

Schuurs‐Hoeijmakers syndrome is a rare disease characterized by intellectual disability and dysmorphic facial features among various physical abnormalities due to PACS1 mutation. To date, 28 patients with a recurrent de novo PACS1 mutation (c.607C > T) have been reported, primarily in Western populations. Here, we describe two Japanese patients with Schuurs‐Hoeijmakers syndrome with a recurrent PACS1 mutation. In addition to the typical clinical symptoms, each patient presented novel clinical phenotypes. One patient presented with involuntary movements and was treated with trihexyphenidyl hydrochloride. We hypothesized that the PACS1 mutation leads to an inherent dopaminergic insufficiency that underlies the developing symptoms along with the neurodevelopmental processes. The second patient was diagnosed with lipomyelomeningocele during an examination for severe constipation at the age of 2 years and 8 months. The diagnosis of lipomyelomeningocele in this patient was delayed due to the lack of cutaneous lesions. As the majority of patients with PACS1 mutation present constipation, underdiagnosis of lipomyelomeningocele is a possibility. As the phenotypic expansion of the patients with Schuurs‐Hoeijmakers syndrome was not fully recognized, additional studies are needed to clarify the clinical spectrum.

We report a patient with autism and cleft lip and palate carrying a de novo heterozygous AUTS2 mutation, c.1464_1467del ACTC (p.Tyr488*). Although the causal relationship between cleft lip and palate and this mutation is unclear, this case report may expand the clinical phenotype of AUTS2 syndrome.

Extensive multilobar cortical dysplasias occasionally occur in children and can induce seizure onset in early infancy, causing severe epileptic encephalopathy. Surgical interventions in early infancy, such as disconnection of large parts of the brain, are challenging because of the degree of invasiveness and carry greater risks in infants compared with older children. Here we report the successful treatment of intractable epilepsy with multilobar cortical dysplasias in the posterior cortex by posterior disconnection in three infants (age 3 months). The patients showed good postoperative recovery and exhibited excellent seizure control at follow-up evaluation within a year after surgery. Developmental catch-up was also achieved and no early complications have been detected to date. Use of the posterior disconnection technique for early-stage extensive multilobar cortical dysplasias can result in good seizure control and developmental progress with little perioperative morbidity. However, the efficacy of this surgical technique needs to be verified with long-term follow up after surgery.

Wiedemann-Steiner syndrome (WDSTS) is an autosomal dominant disorder characterized by hypertrichosis, intellectual disability, and dysmorphic facial appearances (down-slanted vertically narrow palpebral fissures, wide nasal bridge, broad nasal tip, and thick eyebrows). In 2012, Jones and co-workers identified heterozygous mutations in KMT2A (lysine methyltransferase 2A) as the molecular cause of WDSTS. Although the phenotype of this syndrome continues to expand, the associated features are not fully understood. Here, we report WDSTS in a 12-year-old Japanese boy with a novel nonsense mutation in KMT2A. He had right preaxial polydactyly, which has not been previously reported in WDSTS. We could not identify a causal relationship between the KMT2A mutation and preaxial polydactyly, and cannot exclude the preaxial polydactyly is a simple coincidence. We summarized the clinical features of WDSTS associated with KMT2A mutation and discussed the cardinal symptoms in detail.