Browsing by Author "Moore, GE"
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- Gain-of-function mutations in the phosphatidylserine synthase 1 (PTDSS1) gene cause Lenz-Majewski syndromePublication . Sousa, SB; Jenkins, D; Chanudet, E; Tasseva, G; Ishida, M; Anderson, G; Docker, J; Ryten, M; Sá, J; Saraiva, JM; Barnicoat, A; Scott, R; Calder, A; Wattanasirichaigoon, D; Chrzanowska, K; Simandlová, M; Van Maldergem, L; Stanier, P; Beales, PL; Vance, JE; Moore, GELenz-Majewski syndrome (LMS) is a syndrome of intellectual disability and multiple congenital anomalies that features generalized craniotubular hyperostosis. By using whole-exome sequencing and selecting variants consistent with the predicted dominant de novo etiology of LMS, we identified causative heterozygous missense mutations in PTDSS1, which encodes phosphatidylserine synthase 1 (PSS1). PSS1 is one of two enzymes involved in the production of phosphatidylserine. Phosphatidylserine synthesis was increased in intact fibroblasts from affected individuals, and end-product inhibition of PSS1 by phosphatidylserine was markedly reduced. Therefore, these mutations cause a gain-of-function effect associated with regulatory dysfunction of PSS1. We have identified LMS as the first human disease, to our knowledge, caused by disrupted phosphatidylserine metabolism. Our results point to an unexplored link between phosphatidylserine synthesis and bone metabolism.
- Intellectual disability, coarse face, relative macrocephaly, and cerebellar hypotrophy in two sistersPublication . Sousa, SB; Ramos, F; Garcia, P; Pais, RP; Paiva, C; Beales, PL; Moore, GE; Saraiva, JM; Hennekam, RCWe report on two Portuguese sisters with a very similar phenotype characterized by severe intellectual disability, absent speech, relative macrocephaly, coarse face, cerebellar hypotrophy, and severe ataxia. Additional common features include increased thickness of the cranial vault, delayed dental eruption, talipes equino-varus, clinodactyly, and camptodactyly of the fifth finger. The older sister has retinal dystrophy and the younger sister has short stature. Their parents are consanguineous. We suggest this condition constitutes a previously unreported autosomal recessive entity.
- Intellectual disability, unusual facial morphology and hand anomalies in sibsPublication . Sousa, SB; Venâncio, M; Chanudet, E; Palmer, R; Ramos, L; Beales, PL; Moore, GE; Saraiva, JM; Hennekam, RCHere we report on a Portuguese family with three sisters who shared moderate intellectual disability, unusual facial morphology (short palpebral fissures; broad nasal tip; thin upper and lower vermillion; broad and pointed chin) and hand anomalies in two of them (short left third and fifth right metacarpals in one case; marked syndactyly between the third and fourth fingers in another). One of the sisters had microcephaly and short stature, and the other two were obese. Obesity and somewhat similar facial features were also present in the otherwise healthy mother. Despite the overlap with several known syndromes (Albright osteodystrophy; Filippi syndrome; Rubinstein-Taybi syndrome; microdeletion 2q37), we suggest this condition is previously unreported, and most likely displays an autosomal recessive pattern of inheritance.
- Mutations in SNX14 cause a distinctive autosomal-recessive cerebellar ataxia and intellectual disability syndromePublication . Thomas, AC; Williams, H; Setó-Salvia, N; Bacchelli, C; Jenkins, D; O'Sullivan, M; Mengrelis, K; Ishida, M; Ocaka, L; Chanudet, E; James, C; Lescai, F; Anderson, G; Morrogh, D; Ryten, M; Duncan, AJ; Pai, YJ; Saraiva, JM; Ramos, F; Farren, B; Saunders, D; Vernay, B; Gissen, P; Straatmaan-Iwanowska, A; Baas, F; Wood, NW; Hersheson, J; Houlden, H; Hurst, J; Scott, R; Bitner-Glindzicz, M; Moore, GE; Sousa, SB; Stanier, PIntellectual disability and cerebellar atrophy occur together in a large number of genetic conditions and are frequently associated with microcephaly and/or epilepsy. Here we report the identification of causal mutations in Sorting Nexin 14 (SNX14) found in seven affected individuals from three unrelated consanguineous families who presented with recessively inherited moderate-severe intellectual disability, cerebellar ataxia, early-onset cerebellar atrophy, sensorineural hearing loss, and the distinctive association of progressively coarsening facial features, relative macrocephaly, and the absence of seizures. We used homozygosity mapping and whole-exome sequencing to identify a homozygous nonsense mutation and an in-frame multiexon deletion in two families. A homozygous splice site mutation was identified by Sanger sequencing of SNX14 in a third family, selected purely by phenotypic similarity. This discovery confirms that these characteristic features represent a distinct and recognizable syndrome. SNX14 encodes a cellular protein containing Phox (PX) and regulator of G protein signaling (RGS) domains. Weighted gene coexpression network analysis predicts that SNX14 is highly coexpressed with genes involved in cellular protein metabolism and vesicle-mediated transport. All three mutations either directly affected the PX domain or diminished SNX14 levels, implicating a loss of normal cellular function. This manifested as increased cytoplasmic vacuolation as observed in cultured fibroblasts. Our findings indicate an essential role for SNX14 in neural development and function, particularly in development and maturation of the cerebellum.