scholarly journals Novel Hemizygous Missense Variant of Spermine Synthase (SMS) Gene Causes Snyder-Robinson Syndrome in a Four-Year-Old Boy

2021 ◽  
pp. 1-6
Author(s):  
Stella Mouskou ◽  
Adamantios Katerelos ◽  
Artemis Doulgeraki ◽  
Sofia Leka-Emiri ◽  
Emmanouil Manolakos ◽  
...  

Snyder-Robinson syndrome (SRS) is an extremely rare X-linked intellectual disability syndrome (MRXSSR; MIM #309583). The main clinical features of SRS include psychomotor delay, hypotonia, and asthenic-type body habitus – reduced body weight and bone abnormalities (osteoporosis, fractures, kyphoscoliosis). We report a case of SRS with a hemizygous missense variant in the <i>SMS</i> gene,c.334C&#x3e;G (p.Pro112Ala), in a 4-year-old boy, who initially developed hypotonia, delayed motor skills, and subsequently epilepsy. This variant in <i>SMS</i> was found to be de novo. To the best of our knowledge, this novel <i>SMS</i> gene variant has never been previously reported in disease-related variation databases, such as ClinVar or HGMD.

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Yoshitaka Hiromoto ◽  
Yoshiteru Azuma ◽  
Yuichi Suzuki ◽  
Megumi Hoshina ◽  
Yuri Uchiyama ◽  
...  

AbstractPathogenic FLNA variants can be identified in patients with seizures accompanied by periventricular nodular heterotopia (PVNH). It is unusual to find FLNA aberrations in epileptic patients without PVNH on brain imaging. We report a boy with cryptogenic West syndrome followed by refractory seizures and psychomotor delay. We performed whole-exome sequencing and identified a de novo missense variant in FLNA. It is noteworthy that this patient showed no PVNH. As no other pathogenic variants were found in epilepsy-related genes, this FLNA variant likely caused West syndrome but with no PVNH.


2021 ◽  
pp. mcs.a006122
Author(s):  
Mohammad Marhabaie ◽  
Scott E Hickey ◽  
Katherine E Miller ◽  
Olivia Grischow ◽  
Kathleen M Schieffer ◽  
...  

There is increasing recognition for the contribution of genetic mosaicism to human disease, particularly as high-throughput sequencing has enabled detection of sequence variants at very low allele frequencies. Here, we describe an infant male who presented at 9 months of age with hypotonia, dysmorphic features, congenital heart disease, hyperinsulinemic hypoglycemia, hypothyroidism, and bilateral sensorineural hearing loss. Whole-genome sequencing of the proband and the parents uncovered an apparent de novo mutation in the X-linked SMS gene. SMS encodes spermine synthase, which catalyzes the production of spermine from spermidine. Inactivation of the SMS gene disrupts the spermidine/spermine ratio, resulting in Snyder-Robinson syndrome. The variant in our patient is absent from the gnomAD and ExAC databases and causes a missense change (p.Arg130Cys) predicted to be damaging by most in silico tools. While Sanger sequencing confirmed the de novo status in our proband, PCR and deep targeted resequencing to ~84,000-175,000x depth revealed that the variant is present in blood from the unaffected mother at ~3% variant allele frequency. Our findings thus provided a long-sought diagnosis for the family while highlighting the role of parental mosaicism in severe genetic disorders.


2019 ◽  
Vol 28 (5) ◽  
pp. 674-678
Author(s):  
Federico Tessadori ◽  
Atteeq U. Rehman ◽  
Jacques C. Giltay ◽  
Fan Xia ◽  
Haley Streff ◽  
...  

AbstractWe report here a de novo missense variant in HIST1H4J resulting in a complex syndrome combining growth delay, microcephaly and intellectual disability. Trio whole exome sequencing (WES) revealed that the proband was heterozygous for a de novo c.274 A > G p.(K91E) variant in HIST1H4J, a gene not yet associated with human disease. The patient presented with profound intellectual disability, microcephaly, and dysmorphic facial features. Functional consequences of the identified de novo missense variant were evaluated in zebrafish embryos, where they affected general development, especially resulting in defective head organs and reduced body axis length. Our results show that the monoallelic p.K91E substitution on HIST1H4J underlies a human syndrome that is genetically and phenotypically akin to the HIST1H4C-associated neurodevelopmental disorder resulting from p.K91A and p.K91Q substitions in HIST1H4C. The highly overlapping patient phenotypes highlight functional similarities between HIST1H4J and HIST1H4C perturbations, establishing the singular importance of K91 across histone H4 genes for vertebrate development.


2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Giada Moresco ◽  
Jole Costanza ◽  
Carlo Santaniello ◽  
Ornella Rondinone ◽  
Federico Grilli ◽  
...  

Abstract Background De novo pathogenic variants in the DDX3X gene are reported to account for 1–3% of unexplained intellectual disability (ID) in females, leading to the rare disease known as DDX3X syndrome (MRXSSB, OMIM #300958). Besides ID, these patients manifest a variable clinical presentation, which includes neurological and behavioral defects, and abnormal brain MRIs. Case presentation We report a 10-year-old girl affected by delayed psychomotor development, delayed myelination, and polymicrogyria (PMG). We identified a novel de novo missense mutation in the DDX3X gene (c.625C > G) by whole exome sequencing (WES). The DDX3X gene encodes a DEAD-box ATP-dependent RNA-helicase broadly implicated in gene expression through regulation of mRNA metabolism. The identified mutation is located just upstream the helicase domain and is suggested to impair the protein activity, thus resulting in the altered translation of DDX3X-dependent mRNAs. The proband, presenting with the typical PMG phenotype related to the syndrome, does not show other clinical signs frequently reported in presence of missense DDX3X mutations that are associated with a most severe clinical presentation. In addition, she has brachycephaly, never described in female DDX3X patients, and macroglossia, that has never been associated with the syndrome. Conclusions This case expands the knowledge of DDX3X pathogenic variants and the associated DDX3X syndrome phenotypic spectrum.


Author(s):  
Rubina Mulchandani ◽  
Ambalam M. Chandrasekaran ◽  
Roopa Shivashankar ◽  
Dimple Kondal ◽  
Anurag Agrawal ◽  
...  

Abstract Background Adults in urban areas spend almost 77% of their waking time being inactive at workplaces, which leaves little time for physical activity. The aim of this systematic review and meta-analysis was to synthesize evidence for the effect of workplace physical activity interventions on the cardio-metabolic health markers (body weight, waist circumference, body mass index (BMI), blood pressure, lipids and blood glucose) among working adults. Methods All experimental studies up to March 2018, reporting cardio-metabolic worksite intervention outcomes among adult employees were identified from PUBMED, EMBASE, COCHRANE CENTRAL, CINAHL and PsycINFO. The Cochrane Risk of Bias tool was used to assess bias in studies. All studies were assessed qualitatively and meta-analysis was done where possible. Forest plots were generated for pooled estimates of each study outcome. Results A total of 33 studies met the eligibility criteria and 24 were included in the meta-analysis. Multi-component workplace interventions significantly reduced body weight (16 studies; mean diff: − 2.61 kg, 95% CI: − 3.89 to − 1.33) BMI (19 studies, mean diff: − 0.42 kg/m2, 95% CI: − 0.69 to − 0.15) and waist circumference (13 studies; mean diff: − 1.92 cm, 95% CI: − 3.25 to − 0.60). Reduction in blood pressure, lipids and blood glucose was not statistically significant. Conclusions Workplace interventions significantly reduced body weight, BMI and waist circumference. Non-significant results for biochemical markers could be due to them being secondary outcomes in most studies. Intervention acceptability and adherence, follow-up duration and exploring non-RCT designs are factors that need attention in future research. Prospero registration number: CRD42018094436.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Renata R. Braga ◽  
Barbara M. Crisol ◽  
Rafael S. Brícola ◽  
Marcella R. Sant’ana ◽  
Susana C. B. R. Nakandakari ◽  
...  

AbstractThe maintenance of mitochondrial activity in hypothalamic neurons is determinant to the control of energy homeostasis in mammals. Disturbs in the mitochondrial proteostasis can trigger the mitonuclear imbalance and mitochondrial unfolded protein response (UPRmt) to guarantee the mitochondrial integrity and function. However, the role of mitonuclear imbalance and UPRmt in hypothalamic cells are unclear. Combining the transcriptomic analyses from BXD mice database and in vivo experiments, we demonstrated that physical training alters the mitochondrial proteostasis in the hypothalamus of C57BL/6J mice. This physical training elicited the mitonuclear protein imbalance, increasing the mtCO-1/Atp5a ratio, which was accompanied by high levels of UPRmt markers in the hypothalamus. Also, physical training increased the maximum mitochondrial respiratory capacity in the brain. Interestingly, the transcriptomic analysis across several strains of the isogenic BXD mice revealed that hypothalamic mitochondrial DNA-encoded genes were negatively correlated with body weight and several genes related to the orexigenic response. As expected, physical training reduced body weight and food intake. Interestingly, we found an abundance of mt-CO1, a mitochondrial DNA-encoded protein, in NPY-producing neurons in the lateral hypothalamus nucleus of exercised mice. Collectively, our data demonstrated that physical training altered the mitochondrial proteostasis and induced the mitonuclear protein imbalance and UPRmt in hypothalamic cells.


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