We present a case of suspected CDKL5 deficiency disorder (CDD) in which a novel intragenic multi-exonic duplication in the CDKL5 gene was identified using next-generation sequencing and multiple ligation-dependent probe amplification. This duplication was assumed to result in a shift of the reading frame and the introduction of a premature stop codon. This case highlights the importance of careful phenotyping and comprehensive genetic testing to detect rare structural variants in CDD patients.
View Article and Find Full Text PDFPurpose: Diffuse villous hyperplasia of the choroid plexus (DVHCP) and choroid plexus papilloma (CPP) are rare benign tumors usually diagnosed as a result of progressive hydrocephalus, especially in childhood. We present the case of a Japanese boy diagnosed with progressive hydrocephalus due to DVHCP.
Methods: Case: A 2-year and 3-month-old Japanese boy was found to have delayed motor development (equivalent to 1 year and 2 months old), an enlarged head circumference of 51 cm within + 1.
Purpose: To summarise the clinical, molecular and biochemical phenotype of mannosyl-oligosaccharide glucosidase-related congenital disorders of glycosylation (MOGS-CDG), which presents with variable clinical manifestations, and to analyse which clinical biochemical assay consistently supports diagnosis in individuals with bi-allelic variants in .
Methods: Phenotypic characterisation was performed through an international and multicentre collaboration. Genetic testing was done by exome sequencing and targeted arrays.
Neurobeachin (NBEA) was initially identified as a candidate gene for autism. Recently, variants in NBEA have been associated with neurodevelopmental delay and childhood epilepsy. Here, we report on a novel NBEA missense variant (c.
View Article and Find Full Text PDFJ Inherit Metab Dis
September 2020
The transmembrane domain recognition complex (TRC) targets cytoplasmic C-terminal tail-anchored (TA) proteins to their respective membranes in the endoplasmic reticulum (ER), Golgi, and mitochondria. It is composed of three proteins, GET4, BAG6, and GET5. We identified an individual with compound heterozygous missense variants (p.
View Article and Find Full Text PDFAminoacyl-tRNA synthetases (ARSs) are essential enzymes responsible for charging tRNA molecules with cognate amino acids. Consistent with the essential function and ubiquitous expression of ARSs, mutations in 32 of the 37 ARS-encoding loci cause severe, early-onset recessive phenotypes. Previous genetic and functional data suggest a loss-of-function mechanism; however, our understanding of the allelic and locus heterogeneity of ARS-related disease is incomplete.
View Article and Find Full Text PDFVici syndrome is a rare, autosomal recessive, multisystem disorder, characterized by agenesis of the corpus callosum, cataracts, psychomotor delay, cardiomyopathy, hypopigmentation, and recurrent infections. Mutations in the ectopic P-granules autophagy protein 5 homolog gene (EPG5), which encodes a key autophagy regulator, are responsible for this syndrome. A 3-year-old Japanese girl manifesting similar symptoms to those found in patients with Vici syndrome showed intractable diarrhea, rather than immunodeficiency.
View Article and Find Full Text PDFMicrodeletions in the 1q44 region encompassing the HNRNPU gene have been associated with infantile spasms and hemiconvulsion-hemiplegia-epilepsy syndrome. Recent studies have revealed that heterozygous HNRNPU variants resulted in early onset epilepsy and severe intellectual disability. A de novo frameshift mutation in HNRNPU was identified in a 5-year-old boy with developmental delay associated with Rett-like features including stereotypic hand movements and respiratory abnormalities with episode of apnea and hyperpnea followed by falling.
View Article and Find Full Text PDFEven now, only a portion of leukodystrophy patients are correctly diagnosed, though various causative genes have been identified. In the present report, we describe a case of adult-onset leukodystrophy in a woman with ovarian failure. By whole-exome sequencing, a compound heterozygous mutation consisting of NM_020745.
View Article and Find Full Text PDFLeukoencephalopathies are heterogeneous entities with white matter abnormalities. Mutations of the gene encoding hepatic and glial cell adhesion molecule (HEPACAM) located on 11q24 are related to one of the leukoencephalopathies: megalencephalic leukoencephalopathy with subcortical cysts type 2 (MLC2). Genomic copy number aberrations were analyzed by microarray comparative hybridization for two patients.
View Article and Find Full Text PDFGlycine encephalopathy (GCE) is a rare autosomal recessive disorder caused by defects in the glycine cleavage complex. Here we report a patient with GCE and elevated level of glycine in both the serum and the cerebrospinal fluid. Trio-based whole-exome sequencing identified novel compound heterozygous mutations (c.
View Article and Find Full Text PDFl-2-Hydroxyglutaric aciduria (l-2-HGA) is a rare inborn error of metabolism. Mainly, patients with this disorder exhibit neurological symptoms and characteristic neuroradiological findings, such as subcortical white matter abnormalities, which are believed to be caused by the toxicity of the accumulation of l-2-hydroxyglutaric acid. A genotype-first approach of the whole exome sequence was used to identify compound heterozygous mutations, c.
View Article and Find Full Text PDFBackground: Recent development of genetic analyses enabled us to reveal underlying genetic causes of the patients with epileptic encephalopathy in infancy. Mutations of voltage-gated sodium channel type I alpha subunit gene (SCN1A) are to be causally related with several phenotypes of epilepsy, generalized epilepsy with febrile seizure plus (GEFS+), Dravet syndrome, and other infantile epileptic encephalopathies. In addition to SCN1A, contiguous genes such as SCN2A and SCN3A in 2q24.
View Article and Find Full Text PDFObjective: Vanishing white matter disease (VWM) is a chronic, progressive leukoencephalopathy associated with episodes of rapid deterioration following minor stress events such as head traumas or infectious disorders. The white matter of the patients with VWM exhibits characteristic radiological findings.
Method: The genes encoding all five subunits of eukaryotic translation initiation factor 2B (EIF2B) were analyzed in patients, who were tentatively diagnosed with VWM, by Sanger sequencing.
Patients with microdeletions in the 19p13.2 chromosomal region show developmental delays, overgrowth, and distinctive features with big head appearances. These manifestations are now recognized as Sotos syndrome-like features (Sotos syndrome 2) or Malan syndrome.
View Article and Find Full Text PDFObjective: Monosomy 1p36 syndrome is the most commonly observed subtelomeric deletion syndrome. Patients with this syndrome typically have common clinical features, such as intellectual disability, epilepsy, and characteristic craniofacial features.
Method: In cooperation with academic societies, we analyzed the genomic copy number aberrations using chromosomal microarray testing.
1p36 deletion syndrome is one of the most common subtelomeric deletion syndromes. Obesity is frequently observed in patients with this syndrome. Thus, it is important to evaluate the growth status of an individual patient.
View Article and Find Full Text PDFCherubism is a rare genetic disorder characterized by progressive facial deformity caused by non-neoplastic bone lesions in the mandible and/or the maxilla. Src homology-3 binding protein 2 gene (SH3BP2) has been found to be the responsible gene, with alterations in six amino acids noted in patients with this condition. Recently, mutations in this domain have been found to cause stabilization of SH3BP2 by uncoupling with tankyrase.
View Article and Find Full Text PDFOral-facial-digital syndrome type 1 (OFD1; MIM 311200) is characterized by multiple anomalies of the oral cavity, face and digits. We report a family with OFD1, where two female siblings and their mother shared the same mutation of the responsible gene (OFD1) c.1193_1196delAATC.
View Article and Find Full Text PDFThe majority of Xq22 duplications seen in patients with Pelizaeus-Merzbacher disease (PMD) include proteolipid protein 1 (PLP1), the gene responsible for PMD, and neighboring genes. Some cases result from larger duplications up to 7 Mb in size. In comparison, the deletions including PLP1 seen in PMD patients are small.
View Article and Find Full Text PDFMicrodeletions in the 15q22 region have not been well documented. We collected genotype and phenotype data from five patients with microdeletions involving 15q22.2, which were between 0.
View Article and Find Full Text PDFEpilepsy of infancy with migrating focal seizures (EIFMS) is a rare, early-onset epileptic encephalopathy characterized by polymorphous focal seizures. De novo mutations of KCNT1 have been identified in cases of this disorder. We encountered a sporadic patient with EIFMS, who suffered tonic convulsions at the age of 9 days.
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