Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP), previously known as macrocephaly-cutis marmorata telangiectatica congenita and macrocephaly-capillary malformation syndrome, is a rare multiple-malformation syndrome that is characterized by progressive megalencephaly, capillary malformations of the midline face and body, or distal limb anomalies such as syndactyly. Herein, we report a female infant case that satisfies the recently proposed criteria of MCAP and describe the distinctive neuroradiological and morphological features. We have also reviewed recently published reports and the diagnostic criteria proposed by various authors in order to facilitate the clinical diagnosis of these children in pediatric neurology clinics.
Capillaries ; Child ; Diagnosis ; Extremities ; Female ; Humans ; Hypertrophy ; Infant ; Korea* ; Megalencephaly ; Neurology ; Polymicrogyria ; Syndactyly

No abstract available.
Polymicrogyria ; Megalencephaly ; Skin Diseases, Vascular ; Telangiectasis ; Abnormalities, Multiple ; Capillaries ; Vascular Malformations

Smith-Kingsmore syndrome (SKS; OMIM 616638), also known as macrocephaly-intellectual disability-neurodevelopmental disorder-small thorax syndrome (MINDS; ORPHA 457485), is a rare autosomal dominant disorder, the prevalence of which is not known. It is caused by a heterozygous germline mutation in MTOR (OMIM 601231). Ten different MTOR germline mutations in 27 individuals have been reported in the medical literature to date. These were all gain-of-function missense variants, and about half of the 27 individuals had c.5395G>A p.(Glu1799Lys) in MTOR. Here, I report for the first time a Korean patient with the heterozygous germline mutation c.5395G>A p.(Glu1799Lys) in MTOR. It was found to be a de novo mutation, which was identified by whole-exome sequencing and confirmed by Sanger sequencing. The patient showed typical clinical features of SKS, including macrocephaly/megalencephaly; moderate intellectual disability; seizures; behavioral problems; and facial dysmorphic features of curly hair, frontal bossing, midface hypoplasia, and hypertelorism.
Databases, Genetic ; Germ-Line Mutation ; Hair ; Humans ; Hypertelorism ; Intellectual Disability ; Megalencephaly ; Prevalence ; Problem Behavior ; Seizures ; Thorax

Trisomy 1 is a rare chromosomal anomaly and has never been reported in Korea. Clinical features of trisomy 1 include macrocephaly, prominent forehead, flat nasal bridge, low set ears, and micrognathia, all of which result in a very distinguishable facial structure. A child with trisomy 1 also suffers from mental retardation and/or developmental delays. In this case report, the child was diagnosed with de novo trisomy 1 without receiving any treatment until visiting our hospital. The child suffered from foot and ankle deformities, leading her unable to stand independently. Here we report the surgical treatment and rehabilitation treatment that enabled the child to walk independently.
Ankle ; Child* ; Congenital Abnormalities ; Ear ; Foot ; Forehead ; Humans ; Intellectual Disability ; Korea ; Megalencephaly ; Micrognathism ; Orthopedic Procedures ; Rehabilitation* ; Trisomy

Cantú syndrome (CS, OMIM 239850) is a very rare autosomal dominantly inherited genetic disease characterized by congenital hypertrichosis, neonatal macrosomia, a distinct facial features such as macrocephaly, and cardiac defects. Since the first description by Cantú et al. in 1982, about 50 cases have been reported to date. Recently, two causative genes for CS has been found by using exome sequencing analyses: ABCC9 and KCNJ8 . Most cases of clinically diagnosed CS have resulted from de novo mutations in ABCC9. In this study, we report three independent Korean children with CS resulting from de novo ABCC9 mutations. Our patients had common clinical findings such as congenital hypertrichosis, distinctive facial features. One of them showed severe pulmonary hypertension and hypertrophic cardiomyopathy, which require medical treatment. And, two patients had a history of patent ductus arteriosus. Although two of our patients had shown early motor developmental delay, it was gradually improved during follow-up periods. Although CS is quite rare, there are the concerns about development of various cardiac problems in the lifetime. Therefore, an accurate diagnosis followed by appropriate management and genetic counseling should be provided to CS patients.
Cardiomyopathy, Hypertrophic ; Child ; Databases, Genetic ; Diagnosis ; Ductus Arteriosus, Patent ; Exome ; Follow-Up Studies ; Genetic Counseling ; Humans ; Hypertension, Pulmonary ; Hypertrichosis ; Megalencephaly

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is one of the phosphatase and tensin homolog hamartoma tumor syndrome with a PTEN gene mutation. It is a rare dominant autosomal disorder characterized by cutaneous lipomas, macrocephaly, intestinal polyps, and developmental delay. Diagnosing this syndrome is important, because it may represent the pediatric phenotype of Cowden syndrome, in which there is an increased risk for malignant tumors in children. Until now, the prevalence of BRRS is unknown. Several dozen cases have been reported in the medical literature, but no case has been reported in Korea. Here we report a case of a 19-year-old girl who was diagnosed with BRRS because of macrocephaly, intellectual disability, and intestinal polyps. Her mother had similar findings and a PTEN mutation. Neither patient had mutations detected by conventional mutation-detection techniques, but a PTEN gene deletion was demonstrated by chromosomal microarray analysis.
Child ; Female ; Gene Deletion ; Hamartoma ; Hamartoma Syndrome, Multiple* ; Humans ; Intellectual Disability ; Intestinal Polyps ; Korea ; Lipoma ; Megalencephaly ; Microarray Analysis* ; Mothers ; Phenotype ; Prevalence ; Young Adult

BACKGROUND AND PURPOSE: A thick corpus callosum (TCC) can be associated with a very grave outcome in fetuses, but its clinical presentation in older children seems to be markedly different. METHODS: The corpus callosum (CC) was defined as thick based on observations and impressions. We reviewed cases of children who were diagnosed as TCC based on brain magnetic resonance imaging (MRI) studies. The pertinent clinical data of these children were collected, and their CCs were measured. RESULTS: Out of 2,552 brain MRI images, those of 37 children were initially considered as showing a TCC. Those initial imaging were reviewed by an experienced neuroradiologist, who confirmed the diagnosis in 34 children (1.3%): 13 had neurofibromatosis-1 (NF-1), 9 had epilepsy, 3 had macrocephaly capillary malformation (MCM) syndrome, 3 had autistic spectrum disorder, 1 had a Chiari-1 malformation, and 1 had increased head circumference. No specific neurologic disorder could be defined in seven children. The measured thickness of the CC in these children was comparable to those published in the literature for adults. CONCLUSIONS: A TCC is a rare brain malformation that can be found in neuropathologies with apparently diverse pathognomonic mechanisms, such as NF-1 and MCM. It is not necessarily associated with life-threatening conditions, instead being a relatively benign finding, different in nature from that reported in fetuses.
Adult ; Brain ; Capillaries ; Child* ; Corpus Callosum* ; Diagnosis ; Epilepsy ; Fetus ; Genetics ; Head ; Humans ; Magnetic Resonance Imaging ; Megalencephaly ; Nervous System Diseases ; Neurofibromatoses ; Neuropathology

Objective: To investigate the clinical manifestations and genetic features of 2 children with Smith-Kingsmore syndrome caused by MTOR gene variation and review the literature. Methods: The clinical data of 2 children carrying MTOR gene variant, diagnosed at Xi'an Children's Hospital from April 2018 to April 2021, were retrospectively summarized."MTOR"and"Smith-Kingsmore syndrome"were used as key words to search at China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, PubMed and OMIM up to August 2021. The characteristics of MTOR gene variation and the clinical phenotype of children with Smith-Kingsmore syndrome were summarized. Results: Two children were both females, aged 1.5 years and 2 years respectively, the onset age were both in infancy. They both had developmental delay, megalencephaly and abnormal face. Both whole exome sequencing revealed a de novo heterozygous missense variant in MTOR gene. One case carried c.5395G>A (p.Glu1799Lys) and the other case carried c.7234G>C (p.Asp2412His). There was no literature of MTOR gene variation in Chinese. So far, a total of 45 cases were reported worldwide with detailed clinical information. Eleven variations in MTOR gene were involved, which were all heterozygous missense mutations. Among them, p.Glu1799Lys was the most common sites (28 cases,62%). Another case carried c.7234G>C (p.Asp2412His) was not reported before. Summarizing the 47 cases (including these 2 cases), 46 cases had developmental delay or intellectual disability, 9 cases had developmental regression,42 cases had megalencephaly, 30 cases had facial malformation,16 cases had hypotonia, 17 cases had autism spectrum disorders, 3 cases had hyperactivity, 3 cases had obsessive compulsive disorder, 13 cases had eye diseases, 11 cases had cutaneous vascular malformation, and 9 cases had hypoglycemia. Conclusions: The main clinical features of Smith-Kingsmore syndrome include megalencephaly, developmental delay or intellectual disability, and facial malformation, which can be combined with epilepsy, autism spectrum disorder, hypotonia, hypoglycemia and so on. The variation of MTOR gene is the cause of Smith-Kingsmore syndrome.
Autism Spectrum Disorder ; Female ; Humans ; Hypoglycemia ; Intellectual Disability/genetics* ; Megalencephaly/genetics* ; Muscle Hypotonia ; Mutation ; Retrospective Studies ; TOR Serine-Threonine Kinases/genetics*

BACKGROUND: Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare inherited disorder characterized by infantile-onset macrocephaly, slow neurologic deterioration, and seizures. Mutations in the causative gene, MLC1, are found in approximately 75% of patients and are inherited in an autosomal recessive manner. We analyzed MLC1 mutations in five unrelated Korean patients with MLC. METHODS: Direct Sanger sequencing was used to identify MLC1 mutations. A founder effect of the p.Ala275Asp variant was demonstrated by haplotype analysis using single-nucleotide polymorphic (SNP) markers. Multiple ligation-dependent probe amplification (MLPA) and comparative genomic hybridization plus SNP array were used to detect exonic deletions or uniparental disomy (UPD). RESULTS: The most prevalent pathogenic variant was c.824C>A (p.Ala275Asp) found in 7/10 (70%) alleles. Two pathogenic frameshift variants were found: c.135delC (p.Cys46Alafs*12) and c.337_353delinsG (p.Ile113Glyfs*4). Haplotype analysis suggested that the Korean patients with MLC harbored a founder mutation in p.Ala275Asp. The p.(Ile113Glyfs*4) was identified in a homozygous state, and a family study revealed that only the mother was heterozygous for this variant. Further analysis of MLPA and SNP arrays for this patient demonstrated loss of heterozygosity of chromosome 22 without any deletion, indicating UPD. The maternal origin of both chromosomes 22 was demonstrated by haplotype analysis. CONCLUSIONS: This study is the first to describe the mutational spectrum of Korean patients with MLC, demonstrating a founder effect of the p.Ala275Asp variant. This study also broadens our understanding of the mutational spectrum of MLC1 by demonstrating a homozygous p.(Ile113Glyfs*4) variant resulting from UPD of chromosome 22.
Alleles ; Chromosomes, Human, Pair 22* ; Comparative Genomic Hybridization ; Exons ; Founder Effect ; Haplotypes ; Humans ; Leukoencephalopathies* ; Loss of Heterozygosity ; Megalencephaly ; Mothers ; Seizures ; Uniparental Disomy*

Tatton-Brown-Rahman Syndrome (TBRS), an overgrowth syndrome caused by heterozygous mutation of DNMT3A, first was described in 2014. Approximately 60 DNMT3A variants, including 32 missense variants, have been reported, with most missense mutations located on the DNMT3A functional domains. Autosomal dominant inheritance by germ-line mutation of DNMT3A has been reported, but vertical transmission within a family is extremely rare. Herein, we report the first Korean family with maternally inherited TBRS due to the novel heterozygous DNMT3A variant c.118G>C p.(Glu40Gln), located outside the main functional domain and identified by multigene panel sequencing. The patient and her mother had typical clinical features, including tall stature during childhood, macrocephaly, intellectual disability, and characteristic facial appearance. TBRS shows milder dysmorphic features than other overgrowth syndromes, potentially leading to underdiagnosis and underestimated prevalence; thus, targeted multigene panel sequencing including DNMT3A will be a useful tool in cases of overgrowth and unexplained mild intellectual disability for early diagnosis and genetic counseling.
Early Diagnosis ; Genetic Counseling ; Germ-Line Mutation ; Growth Disorders ; High-Throughput Nucleotide Sequencing ; Humans ; Intellectual Disability ; Megalencephaly ; Mothers ; Mutation, Missense ; Prevalence ; Sequence Analysis, DNA ; Wills