scholarly journals A Novel Homozygous Truncating Mutation in LAMB2 Gene in a Chinese Uyghur Patient With Severe Phenotype Pierson Syndrome

2019 ◽  
Vol 6 ◽  
Author(s):  
Hong Tao Zhu ◽  
Mireguli Maimaiti ◽  
Chen Cao ◽  
Yan Fei Luo ◽  
Delihuma Julaiti ◽  
...  
Keyword(s):  
Severe Phenotype ◽  
Truncating Mutation ◽  
Pierson Syndrome

scholarly journals A novel LAMB2 gene mutation associated with a severe phenotype in a neonate with Pierson syndrome

2016 ◽  
Vol 21 (1) ◽  
Author(s):  
Boutaina Zemrani ◽  
François Cachat ◽  
Olivier Bonny ◽  
Eric Giannoni ◽  
Jacques Durig ◽  
...  
Keyword(s):  
Gene Mutation ◽  
Severe Phenotype ◽  
Pierson Syndrome

Five-Year Follow-Up and Successful Kidney Transplantation in a Girl with a Severe Phenotype of Pierson Syndrome

Nephron ◽  
2021 ◽  
pp. 1-6
Author(s):  
Aleksandra Sobieszczańska-Droździel ◽  
Ryszard Grenda ◽  
Beata Stefania Lipska-Ziętkiewicz ◽  
Agnieszka Korolczuk ◽  
Wioletta Jarmużek ◽  
...  
Keyword(s):  
Kidney Transplantation ◽  
Neuromuscular Junctions ◽  
Fatal Outcome ◽  
Congenital Nephrotic Syndrome ◽  
Severe Phenotype ◽  
Neurodevelopmental Delay ◽  
Secondary Hypothyroidism ◽  
Gastrointestinal Problems ◽  
Pierson Syndrome

Pierson syndrome (PIERSS) is a rare autosomal recessive disorder characterized by the combination of congenital nephrotic syndrome (CNS) and extrarenal symptoms including ocular malformations and neurodevelopmental deficits. PIERSS is caused by biallelic pathogenic variants in the LAMB2 gene leading to the defects of β2-laminin, the protein mainly expressed in the glomerular basement membrane, ocular structures, and neuromuscular junctions. Severe complications of PIERSS lead to the fatal outcome in early childhood in majority of the cases. We report a case of 5-year-old girl with severe phenotype of PIERSS caused by biallelic functional null variants of the LAMB2 gene. Due to consequences of CNS, the patient required bilateral nephrectomy and peritoneal dialysis since early infancy. The course was additionally complicated by tubulopathy, life-threatening infections, severe hypertension, erythropoietin-resistant anemia, generalized muscular hypotonia, neurogenic bladder, profound neurodevelopmental delay, epilepsy, gastrointestinal problems, secondary hypothyroidism, and necessity of repeated ocular surgery due to microcoria, cataract, and nystagmus. Due to multidisciplinary efforts, at the age of 4 years, the kidney transplantation was possible. Currently, the renal graft has an excellent function; however, the girl presents severe neurodevelopmental delay. The report presents a unique long-term follow-up of severe PIERSS with a few new phenotypical findings. It highlights the clinical problems and challenges in management of this rare condition.

scholarly journals A novel case of concurrent occurrence of demyelinating-polyneuropathy-causing PMP22 duplication and SOX10 gene mutation producing severe hypertrophic neuropathy

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nozomu Matsuda ◽  
Koushi Ootsuki ◽  
Shunsuke Kobayashi ◽  
Ayaka Nemoto ◽  
Hitoshi Kubo ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Neuromuscular Disorders ◽  
Whole Body ◽  
Congenital Hearing Loss ◽  
Severe Phenotype ◽  
Demyelinating Neuropathy ◽  
Magnetic Resonance Neurography ◽  
Peripheral Myelin Protein 22 ◽  
Hypertrophic Neuropathy

Abstract Background Hereditary motor and sensory neuropathy, also referred to as Charcot–Marie–Tooth disease (CMT), is most often caused by a duplication of the peripheral myelin protein 22 (PMP22) gene. This duplication causes CMT type 1A (CMT1A). CMT1A rarely occurs in combination with other hereditary neuromuscular disorders. However, such rare genetic coincidences produce a severe phenotype and have been reported in terms of “double trouble” overlapping syndrome. Waardenburg syndrome (WS) is the most common form of a hereditary syndromic deafness. It is primarily characterized by pigmentation anomalies and classified into four major phenotypes. A mutation in the SRY sex determining region Y-box 10 (SOX10) gene causes WS type 2 or 4 and peripheral demyelinating neuropathy, central dysmyelinating leukodystrophy, WS, and Hirschsprung disease. We describe a 11-year-old boy with extreme hypertrophic neuropathy because of a combination of CMT1A and WS type 2. This is the first published case on the co-occurrence of CMT1A and WS type 2. Case presentation The 11-year-old boy presented with motor developmental delay and a deterioration in unstable walking at 6 years of age. In addition, he had congenital hearing loss and heterochromia iridis. The neurological examination revealed weakness in the distal limbs with pes cavus. He was diagnosed with CMT1A by the fluorescence in situ hybridization method. His paternal pedigree had a history of CMT1A. However, no family member had congenital hearing loss. His clinical manifestation was apparently severe than those of his relatives with CMT1A. In addition, a whole-body magnetic resonance neurography revealed an extreme enlargement of his systemic cranial and spinal nerves. Subsequently, a genetic analysis revealed a heterozygous frameshift mutation c.876delT (p.F292Lfs*19) in the SOX10 gene. He was eventually diagnosed with WS type 2. Conclusions We described a patient with a genetically confirmed overlapping diagnoses of CMT1A and WS type 2. The double trouble with the genes created a significant impact on the peripheral nerves system. Severe phenotype in the proband can be attributed to the cumulative effect of mutations in both PMP22 and SOX10 genes, responsible for demyelinating neuropathy.

scholarly journals A Novel Truncating Mutation in HOMER2 Causes Nonsyndromic Progressive DFNA68 Hearing Loss in a Spanish Family

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 411
Author(s):  
María Lachgar ◽  
Matías Morín ◽  
Manuela Villamar ◽  
Ignacio del Castillo ◽  
Miguel Ángel Moreno-Pelayo
Keyword(s):  
Hearing Loss ◽  
Stop Codon ◽  
Coiled Coil ◽  
Premature Stop Codon ◽  
Scaffolding Protein ◽  
Common Mechanism ◽  
Chinese Family ◽  
Truncating Mutation ◽  
Spanish Family ◽  
Sensory Defect

Nonsyndromic hereditary hearing loss is a common sensory defect in humans that is clinically and genetically highly heterogeneous. So far, 122 genes have been associated with this disorder and 50 of them have been linked to autosomal dominant (DFNA) forms like DFNA68, a rare subtype of hearing impairment caused by disruption of a stereociliary scaffolding protein (HOMER2) that is essential for normal hearing in humans and mice. In this study, we report a novel HOMER2 variant (c.832_836delCCTCA) identified in a Spanish family by using a custom NGS targeted gene panel (OTO-NGS-v2). This frameshift mutation produces a premature stop codon that may lead in the absence of NMD to a shorter variant (p.Pro278Alafs*10) that truncates HOMER2 at the CDC42 binding domain (CBD) of the coiled-coil structure, a region that is essential for protein multimerization and HOMER2-CDC42 interaction. c.832_836delCCTCA mutation is placed close to the previously identified c.840_840dup mutation found in a Chinese family that truncates the protein (p.Met281Hisfs*9) at the CBD. Functional assessment of the Chinese mutant revealed decreased protein stability, reduced ability to multimerize, and altered distribution pattern in transfected cells when compared with wild-type HOMER2. Interestingly, the Spanish and Chinese frameshift mutations might exert a similar effect at the protein level, leading to truncated mutants with the same Ct aberrant protein tail, thus suggesting that they can share a common mechanism of pathogenesis. Indeed, age-matched patients in both families display quite similar hearing loss phenotypes consisting of early-onset, moderate-to-profound progressive hearing loss. In summary, we have identified the third variant in HOMER2, which is the first one identified in the Spanish population, thus contributing to expanding the mutational spectrum of this gene in other populations, and also to clarifying the genotype–phenotype correlations of DFNA68 hearing loss.

scholarly journals Functional tests to guide management in an adult with loss of function of type-1 angiotensin II receptor

2021 ◽  
Author(s):  
Daan H. H. M. Viering ◽  
Anneke P. Bech ◽  
Jeroen H. F. de Baaij ◽  
Eric J. Steenbergen ◽  
A. H. Jan Danser ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Collecting Duct ◽  
Perinatal Period ◽  
Tubular Dysfunction ◽  
Loss Of Function ◽  
Angiotensin Ii Receptor ◽  
Salt Wasting ◽  
Truncating Mutation ◽  
Urinary Potassium

AbstractBackgroundGenetic loss of function ofAGT(angiotensinogen),REN(renin),ACE(angiotensin-converting enzyme), orAGTR1(type-1 angiotensin II receptor) leads to renal tubular dysgenesis (RTD). This syndrome is almost invariably lethal. Most surviving patients reach stage 5 chronic kidney disease at a young age.MethodsHere, we report a 28-year-old male with a homozygous truncating mutation inAGTR1(p.Arg216*), who survived the perinatal period with a mildly impaired kidney function. In contrast to classic RTD, kidney biopsy showed proximal tubules that were mostly normal. During the subsequent three decades, we observed evidence of both tubular dysfunction (hyperkalemia, metabolic acidosis, salt-wasting and a urinary concentrating defect) and glomerular dysfunction (reduced glomerular filtration rate, currently ~30 mL/min/1.73 m2, accompanied by proteinuria). To investigate the recurrent and severe hyperkalemia, we performed a patient-tailored functional test and showed that high doses of fludrocortisone induced renal potassium excretion by 155%. Furthermore, fludrocortisone lowered renal sodium excretion by 39%, which would have a mitigating effect on salt-wasting. In addition, urinary pH decreased in response to fludrocortisone. Opposite effects on urinary potassium and pH occurred with administration of amiloride, further supporting the notion that a collecting duct is present and able to react to fludrocortisone.ConclusionsThis report provides living proof that even truncating loss-of-function mutations inAGTR1are compatible with life and relatively good GFR and provides evidence for the prescription of fludrocortisone to treat hyperkalemia and salt-wasting in such patients.

scholarly journals β-Thalassemia Intermedia in Northern Iraq: A Single Center Experience

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Nasir A. S. Al-Allawi ◽  
Sana D. Jalal ◽  
Ameen M. Mohammad ◽  
Sharaza Q. Omer ◽  
Raji S. D. Markous
Keyword(s):  
Management Practices ◽  
Iron Chelation ◽  
Globin Genes ◽  
Thalassemia Intermedia ◽  
Severe Phenotype ◽  
Contributing Factors ◽  
Northern Iraq ◽  
Single Center Experience ◽  
Skeletal Changes ◽  
Mediterranean Countries

To investigate the molecular basis ofβ-thalassemia intermedia in Northern Iraq and evaluate its management practices, a total of 74 patients from 51 families were enrolled. The patients were clinically and hematologically reevaluated, and had theirβ-thalassemia mutations characterized, as well as the number ofα-globin genes andXmnIGγ−158 (C>T) polymorphism studied. Out of 14β-thalassemia mutations identified, the four most common were IVS-I-6 (T>C) [33.3%], IVS-II-I (G>A) [21.1%], codon 82/83(−G) [10.1%], and codon 8 (−AA) [8.1%]. The most common contributing factors to the less severe phenotype of thalassemia intermedia were found to be the inheritance of mildβ-thalassemia alleles and theXmnI polymorphism, while concomitantα-thalassemia had a limited role. Several complications were documented including: pulmonary hypertension in 20.4%, diabetes mellitus in 1.4%, hypothyroidism in 2.9%, and heart failure in 2.7%, while no documented cases of venous thrombosis were found. Compared to their counterparts in several Mediterranean countries, it appears that our patients were much less frequently transfused and had a lower proportion of patients who were splenectomized, on iron chelation, or hydroxycarbamide therapy. Such practices require further scrutiny to ensure that a better level of care is provided and that growth retardation, skeletal changes, and other complications are prevented or reduced.

Homozygosity for a novel truncating mutation confirms TBX15 deficiency as the cause of Cousin syndrome

2013 ◽  
Vol 161 (12) ◽  
pp. 3161-3165 ◽  
Author(s):  
Esra Dikoglu ◽  
Pelin Ozlem Simsek-Kiper ◽  
Gulen Eda Utine ◽  
Belinda Campos-Xavier ◽  
Koray Boduroglu ◽  
...  
Keyword(s):  
Truncating Mutation
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