Identification of novel CSNK2A1 variants and the genotype-phenotype relationship in patients with Okur-Chung neurodevelopmental syndrome: a case report and systematic literature review.

De novo germline variants of the casein kinase 2α subunit (CK2α) gene (CSNK2A1) have been reported in individuals with the congenital neuropsychiatric disorder Okur-Chung neurodevelopmental syndrome (OCNS). Here, we report on two unrelated children with OCNS and review the literature to explore the genotype-phenotype relationship in OCNS. Both children showed facial dysmorphism, growth retardation, and neuropsychiatric disorders. Using whole-exome sequencing, we identified two novel de novo CSNK2A1 variants: c.479A>G p.(H160R) and c.238C>T p.(R80C). A search of the literature identified 12 studies that provided information on 35 CSNK2A1 variants in various protein-coding regions of CK2α. By quantitatively analyzing data related to these CSNK2A1 variants and their corresponding phenotypes, we showed for the first time that mutations in protein-coding CK2α regions appear to influence the phenotypic spectrum of OCNS. Mutations altering the ATP/GTP-binding loop were more likely to cause the widest range of phenotypes. Therefore, any assessment of clinical spectra for this disorder should be extremely thorough. This study not only expands the mutational spectrum of OCNS, but also provides a comprehensive overview to improve our understanding of the genotype-phenotype relationship in OCNS.

Atrial septal defect in a patient with congenital disorder of glycosylation type 1a: a case report.

BACKGROUND: Atrial septal defect often become more severe when encountered in genetic syndromes. Congenital disorder of glycosylation type 1a is an inherited metabolic disorder associated with mutations in PMM2 gene and can affect almost all organs. Cardiac abnormalities vary greatly in congenital disorder of glycosylation type 1a and congenital heart defects have already been reported, but there is little knowledge about the effect of this inherited disorder on an existing congenital heart defect. Herein we report for the first time on a baby with congenital disorder of glycosylation type 1a with atrial septal defect and make a comparison of changes in atrial septal defect by follow-ups to the age of 3. CASE PRESENTATION: Our patient was an 8-month-old Han Chinese boy. At the initial visit, he presented with recurrent lower respiratory infection, heart murmur, psychomotor retardation, inverted nipples, and cerebellar atrophy. Echocardiography revealed a 8 mm secundum atrial septal defect with left-to-right shunt (Qp/Qs ratio 1.6). Enzyme testing of phosphomannomutase 2 demonstrated decreased levels of phosphomannomutase 2 activities in fibroblasts. Whole exon sequencing showed he was heterozygous for a frameshift mutation (p.I153X) and a missense mutation (p.I132T) in PMM2 gene. The diagnosis of congenital disorder of glycosylation type 1a with atrial septal defect was issued. Now, he is 3-years old at the time of this writing, with the development of congenital disorder of glycosylation type 1a (cerebellar atrophy become more severe and the symptom of nystagmus emerged), the size of atrial septal defect increased to 10 mm and the Qp/Qs ratio increased to 1.9, which suggested exacerbation of the atrial septal defect. Congenital heart defect-associated gene sequencing is then performed and shows there are no pathogenic mutations, which suggested intrinsic cardiac factors are not the cause of exacerbation of the atrial septal defect in our patient and it is reasonable to assume congenital disorder of glycosylation type 1a can worsen the situation of the existing atrial septal defect. CONCLUSIONS: This report highlights the view that congenital disorders of glycosylation type 1a should be excluded when faced with congenital heart defect with cerebellar atrophy or neurodevelopmental delay, especially when the situation of congenital heart defect becomes more and more severe.

[MECP2 duplication syndrome: a clinical analysis of three cases and literature review].

MECP2 duplication syndrome (MDS) is a rare pediatric disease and mainly manifests as delayed motor development, language loss or delay, recurrent infection, severe intellectual disability, epilepsy, autistic symptoms, and early infantile hypotonia. In this article, the three children with this disease were all boys. Cases 1 and 2 had delayed motor development, and language loss or delay as initial manifestations, and case 3 had recurrent infection as initial manifestation. Physical examination showed hypotonia and negative pathological signs in each case. Case 1 had tonic-clonic seizures and electroencephalography showed focal seizures, for which he was given oxcarbazepine, levetiracetam, and clonazepam as the antiepileptic treatment to control seizures. Case 3 experienced one absence seizure and three head-nodding seizures with normal electroencephalographic findings during these seizures, and therefore, he was not given antiepileptic treatment. In each case, recurrent infection was improved with the increase in age, but there were no significant improvements in language or intelligence. Array-based comparative genomic hybridization (aCGH) showed MECP2 duplication in X chromosome in each case, and so they were diagnosed with MDS. MDS should be considered for children with delayed development complicated by recurrent infection and epileptic seizures, and early aCGH helps with the diagnosis of this disease.