Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A Novel Frameshift Homozygous Mutation in DHCR7 with a Known Missense Homozygous Mutation in the PROC in a 6-Year-Old Boy: A Child with Two Rare Genetic Diseases.

ABSTRACT: In the present case report, we described a 6-year-old-boy with developmental delay, mental retardation, lack of speech, skin scars, and 2 to 3 toe syndactyly from healthy consanguineous Turkish parents. The whole exome sequencing (WES) analysis of this patient showed homozygous variant c.418T?>?C p.(Cys140Arg) in PROC gene and novel homozygous variant c.57dupC p.(Asn20Glnfs*2) in the DHCR7 gene. This finding demonstrated that WES is of great value for the diagnosis of two separate genetic disorders in a patient with multiple dysmorphic and other clinical features. It should also be kept in mind that the coexistence of two autosomal recessive diseases could be observed in highly related consanguineous marriages. The combined evaluation of clinical and laboratory data provided extremely valuable insight into the diagnosis of this unique case.

SUBMITTER: Gumus E

PROVIDER: S-EPMC6688884 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

A Novel Frameshift Homozygous Mutation in DHCR7 with a Known Missense Homozygous Mutation in the PROC in a 6-Year-Old Boy: A Child with Two Rare Genetic Diseases.

Gumus Evren E

Journal of pediatric genetics 20190401 3

In the present case report, we described a 6-year-old-boy with developmental delay, mental retardation, lack of speech, skin scars, and 2 to 3 toe syndactyly from healthy consanguineous Turkish parents. The whole exome sequencing (WES) analysis of this patient showed homozygous variant c.418T > C p.(Cys140Arg) in PROC gene and novel homozygous variant c.57dupC p.(Asn20Glnfs*2) in the DHCR7 gene. This finding demonstrated that WES is of great value for the diagnosis of two separate ...[more]

PMID: 31406626

Similar Datasets

Whole Exome Sequencing Identifies a Novel Homozygous Missense Mutation in the CSB Protein-Encoding ERCC6 Gene in a Taiwanese Boy with Cockayne Syndrome.

Project description:Cockayne syndrome (CS) is a rare form of dwarfism that is characterized by progressive premature aging. CS is typically caused by mutations in the excision repair cross-complementing protein group 6 (ERCC6) gene that encodes the CS group B (CSB) protein. Using whole exome sequencing, we recently identified a novel homozygous missense mutation (Leu536Trp) in CSB in a Taiwanese boy with CS. Since the current database (Varsome) interprets this variant as likely pathogenic, we utilized a bioinformatic tool to investigate the impact of Leu536Trp as well as two other variants (Arg453Ter, Asp532Gly) in similar articles on the CSB protein structure stability. We used iterative threading assembly refinement (I-TASSER) to generate a predictive 3D structure of CSB. We calculated the change of mutation energy after residues substitution on the protein stability using I-TASSER as well as the artificial intelligence program Alphafold. The Asp532Gly variant destabilized both modeled structures, while the Leu536Trp variant showed no effect on I-TASSER's model but destabilized the Alphafold's modeled structure. We propose here the first case of CS associated with a novel homozygous missense mutation (Leu536Trp) in CSB. Furthermore, we suggest that the Asp532Gly and Leu536Trp variants are both pathogenic after bioinformatic analysis of protein stability.

| S-EPMC8618937 | biostudies-literature

Homozygous Rare PARN Missense Mutation in Familial Pulmonary Fibrosis.

Project description: Not available

| S-EPMC6423103 | biostudies-literature

Exome Sequencing Identifies a Novel Homozygous Missense ATP13A2 Mutation.

Project description: Not available

| S-EPMC6353396 | biostudies-literature

Intellectual disability associated with a homozygous missense mutation in THOC6.

Project description:BackgroundWe recently described a novel autosomal recessive neurodevelopmental disorder with intellectual disability in four patients from two related Hutterite families. Identity-by-descent mapping localized the gene to a 5.1 Mb region at chromosome 16p13.3 containing more than 170 known or predicted genes. The objective of this study was to identify the causative gene for this rare disorder.Methods and resultsCandidate gene sequencing followed by exome sequencing identified a homozygous missense mutation p.Gly46Arg, in THOC6. No other potentially causative coding variants were present within the critical region on chromosome 16. THOC6 is a member of the THO/TREX complex which is involved in coordinating mRNA processing with mRNA export from the nucleus. In situ hybridization showed that thoc6 is highly expressed in the midbrain and eyes. Cellular localization studies demonstrated that wild-type THOC6 is present within the nucleus as is the case for other THO complex proteins. However, mutant THOC6 was predominantly localized to the cytoplasm, suggesting that the mutant protein is unable to carry out its normal function. siRNA knockdown of THOC6 revealed increased apoptosis in cultured cells.ConclusionOur findings associate a missense mutation in THOC6 with intellectual disability, suggesting the THO/TREX complex plays an important role in neurodevelopment.

| S-EPMC3644499 | biostudies-literature

Association of a homozygous GCK missense mutation with mild diabetes.

Project description:BackgroundHomozygous inactivating GCK mutations have been repeatedly reported to cause severe hyperglycemia, presenting as permanent neonatal diabetes mellitus (PNDM). Conversely, only two cases of GCK homozygous mutations causing mild hyperglycemia have been so far described. We here report a novel GCK mutation (c.1116G>C, p.E372D), in a family with one homozygous member showing mild hyperglycemia.MethodsGCK mutational screening was carried out by Sanger sequencing. Computational analyses to investigate pathogenicity and molecular dynamics (MD) were performed for GCK-E372D and for previously described homozygous mutations associated with mild (n = 2) or severe (n = 1) hyperglycemia, used as references.ResultsOf four mildly hyperglycemic family-members, three were heterozygous and one, diagnosed in the adulthood, was homozygous for GCK-E372D. Two nondiabetic family members carried no mutations. Fasting glucose (p = 0.016) and HbA1c (p = 0.035) correlated with the number of mutated alleles (0-2). In-silico predicted pathogenicity was not correlated with the four mutations' severity. At MD, GCK-E372D conferred protein structure flexibility intermediate between mild and severe GCK mutations.ConclusionsWe present the third case of homozygous GCK mutations associated with mild hyperglycemia, rather than PNDM. Our in-silico analyses support previous evidences suggesting that protein stability plays a role in determining clinical severity of GCK mutations.

| S-EPMC6625123 | biostudies-literature

A homozygous missense mutation in human KLOTHO causes severe tumoral calcinosis.

Project description:Familial tumoral calcinosis is characterized by ectopic calcifications and hyperphosphatemia due to inactivating mutations in FGF23 or UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3). Herein we report a homozygous missense mutation (H193R) in the KLOTHO (KL) gene of a 13-year-old girl who presented with severe tumoral calcinosis with dural and carotid artery calcifications. This patient exhibited defects in mineral ion homeostasis with marked hyperphosphatemia and hypercalcemia as well as elevated serum levels of parathyroid hormone and FGF23. Mapping of H193R mutation onto the crystal structure of myrosinase, a plant homolog of KL, revealed that this histidine residue was at the base of the deep catalytic cleft and mutation of this histidine to arginine should destabilize the putative glycosidase domain (KL1) of KL, thereby attenuating production of membrane-bound and secreted KL. Indeed, compared with wild-type KL, expression and secretion of H193R KL were markedly reduced in vitro, resulting in diminished ability of FGF23 to signal via its cognate FGF receptors. Taken together, our findings provide what we believe to be the first evidence that loss-of-function mutations in human KL impair FGF23 bioactivity, underscoring the essential role of KL in FGF23-mediated phosphate and vitamin D homeostasis in humans.

| S-EPMC1940239 | biostudies-literature

A homozygous frameshift mutation in the mouse Flg gene facilitates enhanced percutaneous allergen priming.

Project description:Loss-of-function mutations in the FLG (filaggrin) gene cause the semidominant keratinizing disorder ichthyosis vulgaris and convey major genetic risk for atopic dermatitis (eczema), eczema-associated asthma and other allergic phenotypes. Several low-frequency FLG null alleles occur in Europeans and Asians, with a cumulative frequency of approximately 9% in Europe. Here we report a 1-bp deletion mutation, 5303delA, analogous to common human FLG mutations, within the murine Flg gene in the spontaneous mouse mutant flaky tail (ft). We demonstrate that topical application of allergen to mice homozygous for this mutation results in cutaneous inflammatory infiltrates and enhanced cutaneous allergen priming with development of allergen-specific antibody responses. These data validate flaky tail as a useful model of filaggrin deficiency and provide experimental evidence for the hypothesis that antigen transfer through a defective epidermal barrier is a key mechanism underlying elevated IgE sensitization and initiation of cutaneous inflammation in humans with filaggrin-related atopic disease.

| S-EPMC2872154 | biostudies-literature

A homozygous missense mutation in the ciliary gene TTC21B causes familial FSGS.

Project description:Several genes, mainly involved in podocyte cytoskeleton regulation, have been implicated in familial forms of primary FSGS. We identified a homozygous missense mutation (p.P209L) in the TTC21B gene in seven families with FSGS. Mutations in this ciliary gene were previously reported to cause nephronophthisis, a chronic tubulointerstitial nephropathy. Notably, tubular basement membrane thickening reminiscent of that observed in nephronophthisis was present in patients with FSGS and the p.P209L mutation. We demonstrated that the TTC21B gene product IFT139, an intraflagellar transport-A component, mainly localizes at the base of the primary cilium in developing podocytes from human fetal tissue and in undifferentiated cultured podocytes. In contrast, in nonciliated adult podocytes and differentiated cultured cells, IFT139 relocalized along the extended microtubule network. We further showed that knockdown of IFT139 in podocytes leads to primary cilia defects, abnormal cell migration, and cytoskeleton alterations, which can be partially rescued by p.P209L overexpression, indicating its hypomorphic effect. Our results demonstrate the involvement of a ciliary gene in a glomerular disorder and point to a critical function of IFT139 in podocytes. Altogether, these data suggest that this homozygous TTC21B p.P209L mutation leads to a novel hereditary kidney disorder with both glomerular and tubulointerstitial damages.

| S-EPMC4214529 | biostudies-literature

A case report of an acute coronary syndrome in a 10-year-old boy with homozygous familial hypercholesterolaemia.

Project description:BackgroundFamilial hypercholesterolaemia is a well-known disorder, but clinical diagnoses tend to be delayed. Acute coronary syndrome may occur in childhood.Case summaryOur patient, a young boy with homozygous familial hypercholesterolaemia, complained of persistent chest pain at rest and suffered a non-ST-elevation myocardial infarction (NSTEMI). The diagnosis of NSTEMI was made on the basis of his clinical features, dynamic electrocardiogram changes, troponin elevation, and cardiac computed tomography findings. The patient was managed surgically by intrathoracic artery (ITA) bypass graft. During post-operative follow-up, the young patient suffered from angina pectoris from unexpected and exceptional atheroma stenosis on the ITA.DiscussionFamilial hypercholesterolaemia needs to be identified quickly in young patients and lipid lowering therapies should be started without delay.

| S-EPMC7574956 | biostudies-literature

Acromicric dysplasia with stiff skin syndrome-like severe cutaneous presentation in an 8-year-old boy with a missense FBN1 mutation: Case report and literature review.

Project description:BACKGROUND:Acromicric dysplasia is a rare heritable short-stature syndrome with joint stiffness and varying degrees of cutaneous hardness. Stiff skin syndrome is a rare connective tissue disorder characterized by diffusely thick and hard skin from the time of birth. Heterozygous point mutations in the FBN1 have been proposed as the predominant cause of both diseases. METHODS:By performing skin biopsy, X-ray imaging, electrocardiography, as well as whole-genome sequencing and Sanger sequencing, we diagnosed an 8-year-old Chinese boy as acromicric dysplasia with severe skin stiffness caused by a heterogeneous mutation in the FBN1. RESULTS:The patient presented with skin tightness, wrist and ankle stiffness, short stature and limbs, several deformed joints in the extremities, cone-shaped epiphyses, and distinct facial features. He also had a patent foramen ovale and frequent respiratory infections. Skin biopsy showed thickened dermis and excessive collagen aggregation. Alcian blue staining indicated dermal mucopolysaccharide deposition. Mutation analysis revealed a heterozygous missense mutation, c.5243G>A (p.Cys1748Tyr), in exon 42 of the FBN1. CONCLUSION:This is a report about acromicric dysplasia with stiff skin syndrome-like severe cutaneous presentation caused by a single hotspot mutation, further revealing the gene pleiotropy of FBN1.

| S-EPMC7336748 | biostudies-literature