A novel fibrinogen B beta chain frameshift mutation causes congenital afibrinogenaemia

2013 ◽  
Vol 110 (07) ◽  
pp. 76-82 ◽  
Author(s):  
Ziqiang Yu ◽  
Lijuan Cao ◽  
Wei Zhang ◽  
Xia Bai ◽  
Changgeng Ruan ◽  
...  

SummaryCongenital afibrinogenaemia is a rare autosomal recessive disorder caused by various mutations within the fibrinogen genes FGA, FGB and FGG. Ins/del mutations in FGB are extremely rare. We report a patient with afibrinogenaemia who suffered from umbilical cord bleeding and repeated bleeding episodes. His plasma fibrinogen levels could not be detected using the Clauss method and immunological methods. Molecular analyses revealed homozygosity in a novel four bases insertion in codon 40 of FGB exon 2 (g. 2833_2834 ins GTTT), which resulted in a truncated 50-residue polypeptide that contained 11 exceptional abnormal residues. In the transient expression experiments, mutant fibrinogen could be detected at higher level than wild-type fibrinogen in COS-7 cell lysates but not in culture media. These results suggest that the homozygous mutation in FGB could be responsible for congenital afibrinogenaemia in this patient. This frameshift mutation could impair fibrinogen assembly and secretion without influencing the protein synthesis.

Author(s):  
Hasan Akduman ◽  
Dilek Dilli ◽  
Serdar Ceylaner

AbstractCongenital glucose-galactose malabsorption (CGGM) is an autosomal recessive disorder originating from an abnormal transporter mechanism in the intestines. It was sourced from a mutation in the SLC5A1 gene, which encodes a sodium-dependent glucose transporter. Here we report a 2-day-old girl with CGGM who presented with severe hypernatremic dehydration due to diarrhea beginning in the first hours of life. Mutation analysis revealed a novel homozygous mutation NM_000343.3 c.127G > A (p.Gly43Arg) in the SLC5A1 gene. Since CGGM can cause fatal diarrhea in the early neonatal period, timely diagnosis of the disease seems to be essential.


2021 ◽  
Vol 79 (1) ◽  
pp. 25-30
Author(s):  
Emanuela Maderna ◽  
Silvia Visonà ◽  
Vittorio Bolcato ◽  
Veronica Redaelli ◽  
Paola Caroppo ◽  
...  

Nasu-Hakola disease is a rare autosomal recessive disorder associated to mutations in TREM2 and DAP12 genes, neuropathologically characterized by leukoencephalopathy with axonal spheroids. We report the neuropathologic findings of a 51-year-old female with a homozygous mutation (Q33X) of TREM2 gene. Beside severe cerebral atrophy and hallmarks of Nasu-Hakola disease, significant Alzheimer’s disease lesions were present. Neurofibrillary changes showed an atypical topographic distribution being severe at spots in the neocortex while sparing the mesial temporal structures. Our finding suggests that TREM2 genetic defects may favor Alzheimer’s disease pathology with neurofibrillary changes not following the hierarchical staging of cortical involvement identified by Braak.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Ludmilla OGOUMA-AWORET ◽  
Jean-Pierre RABES ◽  
Philippe de MAZANCOURT

Hereditary hemochromatosis is an autosomal recessive disorder with incomplete penetrance that results from excess iron absorption and can lead to chronic liver disease, fibrosis, cirrhosis, and hepatocellular carcinoma. The most common form of hereditary hemochromatosis in Western Europe is due to a homozygous mutation (p.(Cys282Tyr) or C282Y), in the HFE gene which encodes hereditary haemochromatosis protein. In the general European population, the frequency of the homozygous genotype is 0.4%, and this mutation explains up to 95% of hereditary hemochromatosis in France. We report here an improved PCR and restriction endonuclease assay based on multiplex amplification of HFE exon 4 (for C282Y detection), HFE exon 2 (for H63D detection), FZD1 gene (for digestion controls), and two Short Tandem Repeats (SE33 and FGA) for identity monitoring and contamination tracking. Fluorescent primers allow capillary electrophoresis, accurate allele tagging, and sensitive contamination detection.


Blood ◽  
2000 ◽  
Vol 95 (4) ◽  
pp. 1336-1341 ◽  
Author(s):  
Stefano Duga ◽  
Rosanna Asselta ◽  
Elena Santagostino ◽  
Sirous Zeinali ◽  
Tatjana Simonic ◽  
...  

Congenital afibrinogenemia is a rare autosomal recessive disorder characterized by bleeding that varies from mild to severe and by complete absence or extremely low levels of plasma and platelet fibrinogen. Although several mutations in the fibrinogen genes associated with dysfibrinogenemia and hypofibrinogenemia have been described, the genetic defects of congenital afibrinogenemia are largely unknown, except for a recently reported 11-kb deletion of the fibrinogen A-chain gene. Nevertheless, mutation mechanisms other than the deletion of a fibrinogen gene are likely to exist because patients with afibrinogenemia showing no gross alteration within the fibrinogen cluster have been reported. We tested this hypothesis by studying the affected members of two families, one Italian and one Iranian, who had no evidence of large deletions in the fibrinogen genes. Sequencing of the fibrinogen genes in the 2 probands detected 2 different homozygous missense mutations in exons 7 and 8 of the Bβ-chain gene, leading to amino acid substitutions Leu353Arg and Gly400Asp, respectively. Transient transfection experiments with plasmids expressing wild-type and mutant fibrinogens demonstrated that the presence of either mutation was sufficient to abolish fibrinogen secretion. These findings demonstrated that missense mutations in the Bβ fibrinogen gene could cause congenital afibrinogenemia by impairing fibrinogen secretion.


2016 ◽  
Vol 310 (6) ◽  
pp. L519-L531 ◽  
Author(s):  
Saket Ahuja ◽  
Lars Knudsen ◽  
Shashi Chillappagari ◽  
Ingrid Henneke ◽  
Clemens Ruppert ◽  
...  

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder, and some patients with HPS develop pulmonary fibrosis, known as HPS-associated interstitial pneumonia (HPSIP). We have previously reported that HPSIP is associated with severe surfactant accumulation, lysosomal stress, and alveolar epithelial cell type II (AECII) apoptosis. Here, we hypothesized that defective autophagy might result in excessive lysosomal stress in HPSIP. Key autophagy proteins, including LC3B lipidation and p62, were increased in HPS1/2 mice lungs. Electron microscopy demonstrated a preferable binding of LC3B to the interior of lamellar bodies in the AECII of HPS1/2 mice, whereas in wild-type mice it was present on the limiting membrane in addition to the interior of the lamellar bodies. Similar observations were noted in human HPS1 lung sections. In vitro knockdown of HPS1 revealed increased LC3B lipidation and p62 accumulation, associated with an increase in proapoptotic caspases. Overexpression of LC3B decreased the HPS1 knockdown-induced p62 accumulation, whereas rapamycin treatment did not show the same effect. We conclude that loss of HPS1 protein results in impaired autophagy that is restored by exogenous LC3B and that defective autophagy might therefore play a critical role in the development and progression of HPSIP.


2003 ◽  
Vol 370 (3) ◽  
pp. 891-899 ◽  
Author(s):  
Jian WANG ◽  
Guohua CHEN ◽  
Kostas PANTOPOULOS

HFE, an atypical MHC class I type molecule, has a critical, yet still elusive function in the regulation of systemic iron metabolism. HFE mutations are linked to hereditary haemochromatosis type 1, a common autosomal recessive disorder of iron overload. Most patients are homozygous for a C282Y point mutation that abrogates the interaction of HFE with β2-microglobulin (β2M) and, thus, impairs its proper processing and expression on the cell surface. An H63D substitution is also associated with disease. To investigate the function of HFE we have generated clones of human H1299 lung cancer cells that express wild-type, C282Y or H63D HFE under the control of a tetracycline-inducible promoter. Consistent with earlier observations in other cell lines, the expression of wild-type or H63D, but not C282Y, HFE induces an apparent iron-deficient phenotype, manifested in the activation of iron-regulatory protein and concomitant increase in transferrin receptor levels and decrease in ferritin content. This phenotype persists in cells expressing wild-type HFE after transfection with a β2M cDNA. Whereas endogenous β2M is sufficient for the presentation of at least a fraction of chimeric HFE on the cell surface, this effect is stimulated by approx. 2.8-fold in β2M transfectants. The co-expression of exogenous β2M does not significantly affect the half-life of HFE. These results suggest that the apparent iron-deficient phenotype elicited by HFE is not linked to β2M insufficiency.


2008 ◽  
Vol 52 (8) ◽  
pp. 1277-1281 ◽  
Author(s):  
Fernanda Borchers Coeli ◽  
Lúcio Fábio Caldas Ferraz ◽  
Sofia H. V. de Lemos-Marini ◽  
Sumara Zuanazi Pinto Rigatto ◽  
Vera Maria Santoro Belangero ◽  
...  

The apparent mineralocorticoid excess syndrome (AME) is a rare autosomal recessive disorder due to the deficiency of 11β-hydroxysteroid dehydrogenase type 2 enzyme (11beta-HSD2). The 11beta-HSD2 enzyme, encoded by HSD11B2 gene, metabolizes active cortisol in cortisone. Mutations on HSD11B2 gene affect the enzyme activity by leading to an excess of cortisol, which causes its inappropriate access to mineralocorticoid receptor. Therefore, cortisol will bind mineralocorticoid receptor. The human HSD11B2 gene maps to chromosome 16q22 and consists of five exons encoding a protein of 405 amino acids. We present here clinical and molecular studies on a Brazilian boy who was born pre-term after an oligodramnious pregnancy. He was diagnosed as having AME at the age of 26 months. His parents are second cousins. Molecular characterization of the HSD11B2 gene revealed the homozygous mutation p.R186C. The patient described here is the second case of HDS11B2 gene mutation reported in Brazilian patients with AME.


2010 ◽  
Vol 299 (5) ◽  
pp. C1153-C1161 ◽  
Author(s):  
Kris Mahadeo ◽  
Ndeye Diop-Bove ◽  
Daniel Shin ◽  
Ersin Selcuk Unal ◽  
Juliana Teo ◽  
...  

The proton-coupled folate transporter (PCFT-SLC46A1) is required for intestinal folate absorption and is mutated in the autosomal recessive disorder, hereditary folate malabsorption (HFM). This report characterizes properties and requirements of the R376 residue in PCFT function, including a R376Q mutant associated with HFM. Gln, Cys, and Ala substitutions resulted in markedly impaired transport of 5-formyltetrahydrofolate (5-FTHF) and 5-methyltetrahydrofolate (5-MTHF) due to an increase in Kmand decrease in Vmaxin HeLa R1–11 transfectants lacking endogenous folate transport function. In contrast, although the influx Kmfor pemetrexed was increased, transport was fully preserved at saturating concentrations and enhanced for the like-charged R376K- and R376H-PCFT. Pemetrexed and 5-FTHF influx mediated by R376Q-PCFT was markedly decreased at pH 5.5 compared with wild-type PCFT. However, while pemetrexed transport was substantially preserved at low pH (4.5–5.0), 5-FTHF transport remained very low. Electrophysiological studies in Xenopus oocytes demonstrated that 1) the R376Q mutant, like wild-type PCFT, transports protons in the absence of folate substrate, and in this respect has channel-like properties; and 2) the influx Kmmediated by R376Q-PCFT is increased for 5-MTHF, 5-FTHF, and pemetrexed. The data suggest that mutation of the R376 residue to Gln impairs proton binding which, in turn, modulates the folate-binding pocket and depresses the rate of conformational alteration of the carrier, a change that appears to be, in part, substrate dependent.


Author(s):  
Enise Avci Durmusalioglu ◽  
Esra Isik ◽  
Durdugul Ayyildiz Emecen ◽  
Damla Goksen ◽  
Samim Ozen ◽  
...  

Abstract Objectives Childhood osteoporosis is often a consequence of a chronic disease or its treatment. Lysinuric protein intolerance (LPI), a rare secondary cause of the osteoporosis, is an autosomal recessive disorder with clinical features ranging from minimal protein intolerance to severe multisystemic involvement. We report a case diagnosed to have LPI using a Next Generation Sequencing (NGS) panel and evaluate the utility of reverse phenotyping. Case presentation A fifteen-year-old-boy with an initial diagnosis of osteogenesis imperfecta, was referred due to a number of atypical findings accompanying to osteoporosis such as splenomegaly and bicytopenia. A NGS panel (TruSight One Sequencing Panel) was performed and a novel homozygous mutation of c.257G>A (p.Gly86Glu) in the SLC7A7 gene (NM_001126106.2), responsible for LPI, was detected. The diagnosis was confirmed via reverse phenotyping. Conclusions Reverse phenotyping using a multigene panel shortens the diagnostic process.


2021 ◽  
Vol 12 ◽  
Author(s):  
Haihua Lin ◽  
Youhong Fang ◽  
Lin Han ◽  
Jie Chen ◽  
Jingan Lou ◽  
...  

Transient infantile hypertriglyceridemia is a rare autosomal recessive disorder characterized by hypertriglyceridemia, hypohepatia, hepatomegaly, hepatic steatosis and fibrosis in infancy. Mutations in GPD1 gene are considered the causative factor but the underlying mechanism of this disorder is still enigmatic. To date, only 24 different GPD1 mutations have been reported in the literature worldwide with transient infantile hypertriglyceridemia or relevant conditions. Here we report a Chinese girl who developed hepatomegaly hepatic steatosis, elevated transaminase and hypertriglyceridemia from the age of 4 months. A novel homozygous variant c.454C>T (p.Q152*) was found in GPD1 gene by next-generation sequencing. This patient is the 3rd Asian reported with transient infantile hypertriglyceridemia. We summarized the clinical presentations of transient infantile hypertriglyceridemia and also expanded the spectrum of disease-causing mutations in GPD1.


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