Search results for "Heredity"

The broad phenotypic spectrum of PPP2R1A -related neurodevelopmental disorders correlates with the degree of biochemical dysfunction

2021

PURPOSE: Neurodevelopmental disorders (NDD) caused by protein phosphatase 2A (PP2A) dysfunction have mainly been associated with de novo variants in PPP2R5D and PPP2CA, and more rarely in PPP2R1A. Here, we aimed to better understand the latter by characterizing 30 individuals with de novo and often recurrent variants in this PP2A scaffolding Aα subunit. METHODS: Most cases were identified through routine clinical diagnostics. Variants were biochemically characterized for phosphatase activity and interaction with other PP2A subunits. RESULTS: We describe 30 individuals with 16 different variants in PPP2R1A, 21 of whom had variants not previously reported. The severity of developmental delay …

Population Genetics of Latvians in the Context of Admixture between North-Eastern European Ethnic Groups

2018

Abstract This article presents a review on population genetics of Latvians, which alongside Lithuanians are the two extant Baltic speaking populations. The article provides a description of genome-wide single nucleotide polymorphism (SNP) data and contains a comparative analysis of the results of studies performed on classical autosomal genetic markers, mitochondrial DNA (mtDNA) and the non-recombining part of the Y chromosome (NRY), with data on neighbouring populations. The study also covers data of recently performed ancient DNA (aDNA) studies carried out on samples from the territory of today’s Latvia. The results of population genetic studies have shown a mixture of eastern and western…

Total Hemi-overgrowth in Pigmentary Mosaicism of the (Hypomelanosis of) Ito Type: Eight Case Reports.

2016

Abstract Pigmentary mosaicism of the (hypomelanosis of) Ito type is an umbrella term, which includes phenotypes characterized by mosaic hypopigmentation in the form of streaks, whorls, patchy, or more bizarre skin configurations (running along the lines of Blaschko): these cutaneous patterns can manifest as an isolated skin disorder (pigmentary mosaicism of the Ito type) or as a complex malformation syndrome in association with extracutaneous anomalies (most often of the musculoskeletal and/or nervous systems) (hypomelanosis of Ito). Affected individuals are anecdotally reported to have also partial or total body hemi-overgrowth (HOG), which often causes moderate to severe complications. We…

One NF1 Mutation may Conceal Another

2019

Neurofibromatosis type 1 (NF1) is an autosomal dominant disease with complete penetrance but high variable expressivity. NF1 is caused by loss-of-function mutations in the NF1 gene, a negative regulator of the RAS-MAPK pathway. The NF1 gene has one of the highest mutation rates in human disorders, which may explain the outbreak of independent de novo variants in the same family. Here, we report the co-occurrence of pathogenic variants in the NF1 and SPRED1 genes in six families with NF1 and Legius syndrome, using next-generation sequencing. In five of these families, we observed the co-occurrence of two independent NF1 variants. All NF1 variants were classified as pathogenic, according to t…

Harmonising and linking biomedical and clinical data across disparate data archives to enable integrative cross-biobank research

2015

A wealth of biospecimen samples are stored in modern globally distributed biobanks. Biomedical researchers worldwide need to be able to combine the available resources to improve the power of large-scale studies. A prerequisite for this effort is to be able to search and access phenotypic, clinical and other information about samples that are currently stored at biobanks in an integrated manner. However, privacy issues together with heterogeneous information systems and the lack of agreed-upon vocabularies have made specimen searching across multiple biobanks extremely challenging. We describe three case studies where we have linked samples and sample descriptions in order to facilitate glo…

Compassionate use of everolimus for refractory epilepsy in a patient with MTOR mosaic mutation

2020

Abstract The MTOR gene encodes the mechanistic target of rapamycin (mTOR), which is a core component of the PI3K-AKT-mTOR signaling pathway. Postzygotic MTOR variants result in various mosaic phenotypes, referred to in OMIM as Smith-Kinsgmore syndrome or focal cortical dysplasia. We report here the case of a patient, with an MTOR mosaic gain-of-function variant (p.Glu2419Lys) in the DNA of 41% skin cells, who received compassionate off-label treatment with everolimus for refractory epilepsy. This 12-year-old-girl presented with psychomotor regression, intractable seizures, hypopigmentation along Blaschko's lines (hypomelanosis of Ito), asymmetric regional body overgrowth, and ocular anomali…

Extending the ALDH18A1 clinical spectrum to severe autosomal recessive fetal cutis laxa with corpus callosum agenesis

2018

IF 3.822 (2018); International audience

Hypertrophic pachymeningitis and cerebral venous thrombosis in myeloperoxidase-ANCA associated vasculitis

2019

Hypertrophic pachymeningitis (HP) is a circumscribed inflammatory process that thickens meninges with fibrous adhesions. Among the causes of HP, vasculitis and autoimmune disease should be considered; myeloperoxidase (MPO)-antinuclear cytoplasmatic antibodies (ANCA)-positivity can be the only

Brain MRI patterns in MPS IIIB (Sanfilippo syndrome type B): A longitudinal study

2016

Autosomal recessive truncatingMAB21L1mutation associated with a syndromic scrotal agenesis

2016

We report on a boy with a rare malformative association of scrotum agenesis, ophthalmological anomalies, cerebellar malformation, facial dysmorphism and global development delay. The reported patient was carrying a homozygous frameshift in MAB21L1 detected by whole-exome sequencing, considered as the most likely disease-causing variant. Mab21l1 knockout mice present a strikingly similar malformative association of ophthalmological malformations of the anterior chamber and preputial glands hypoplasia. We hypothesize that MAB21L1 haploinsufficiency cause a previously undescribed syndrome with scrotal agenesis, ophthalmological anomalies, facial dysmorphism and gross psychomotor delay as remar…