Identification of the first Alu-mediated large deletion involving the F5 gene in a compound heterozygous patient with severe factor V deficiency

2011 ◽  
Vol 106 (08) ◽  
pp. 296-303 ◽  
Author(s):  
Ilaria Guella ◽  
Elvezia Maria Paraboschi ◽  
Willem A. van Schalkwyk ◽  
Rosanna Asselta ◽  
Stefano Duga

SummaryFactor V (FV) deficiency is a rare autosomal recessive haemorrhagic disorder associated with moderate to severe bleeding symptoms. Conventional mutational screening leads to a complete molecular genetic diagnosis only in about 80–90% of cases. Large gene rearrangements, which could explain at least part of the “missing alleles” have not been reported so far in FV-deficient patients. In this work, we investigated a family with hereditary FV deficiency, in which the proband is compound heterozygous for a 205-Kb deletion, involving the first seven exons of F5, and the entire selectin P, L, and E genes, and for a novel splicing mutation (IVS12+5G>A). The deletion breakpoints, determined by using a combination of semi-quantitative real-time PCR and long PCR assays, occurred within AluY repeat sequences, suggesting an Alu-mediated unequal homologous recombination as the mechanism responsible for the deletion. The in vitro characterisation of the IVS12+5G>A mutation demonstrated that this mutation causes the skipping of exon 12 and the activation of a cryptic splice site. Low levels of residual wild-type splicing were also detectable, in agreement with the notion that the complete absence of FV may be not compatible with life.

Haemophilia ◽  
2018 ◽  
Vol 24 (4) ◽  
pp. 648-656 ◽  
Author(s):  
C. Bulato ◽  
C. Novembrino ◽  
M. Boscolo Anzoletti ◽  
L. Spiezia ◽  
S. Gavasso ◽  
...  
Keyword(s):  
Factor V ◽  

Blood ◽  
2013 ◽  
Vol 122 (23) ◽  
pp. 3825-3831 ◽  
Author(s):  
Francesca Nuzzo ◽  
Claudia Radu ◽  
Marco Baralle ◽  
Luca Spiezia ◽  
Tilman M. Hackeng ◽  
...  

Key Points Homozygosity for the F5 c.1296+268A>G splicing mutation causes life-threatening factor V deficiency. Mutation-specific antisense molecules can correct this splicing defect and restore factor V synthesis in the patient’s megakaryocytes.


Medicine ◽  
2020 ◽  
Vol 99 (5) ◽  
pp. e18947
Author(s):  
Chang-Hun Park ◽  
Min-Seung Park ◽  
Ki-O Lee ◽  
Sun-Hee Kim ◽  
Young Shil Park ◽  
...  

Blood ◽  
2020 ◽  
Vol 136 (17) ◽  
pp. 1933-1945
Author(s):  
Emese Molnár ◽  
Nesrine Radwan ◽  
Gábor Kovács ◽  
Hajnalka Andrikovics ◽  
Frances Henriquez ◽  
...  

Abstract Autoimmune lymphoproliferative syndrome (ALPS) is a rare immunodeficiency caused by mutations in genes affecting the extrinsic apoptotic pathway (FAS, FASL, CASP10). This study evaluated the clinical manifestations, laboratory findings, and molecular genetic results of 215 patients referred as possibly having ALPS. Double-negative T-cell (DNT) percentage and in vitro apoptosis functional tests were evaluated by fluorescence-activated cell sorting; interleukin 10 (IL-10) and IL-18 and soluble FAS ligand (sFASL) were measured by enzyme-linked immunosorbent assay. Genetic analysis was performed by next-generation sequencing. Clinical background data were collected from patients’ records. Patients were categorized into definite, suspected, or unlikely ALPS groups, and laboratory parameters were compared among these groups. Of 215 patients, 38 met the criteria for definite ALPS and 17 for suspected ALPS. The definite and suspected ALPS patient populations showed higher DNT percentages than unlikely ALPS and had higher rates of lymphoproliferation. Definite ALPS patients had a significantly more abnormal in vitro apoptosis function, with lower annexin, than patients with suspected ALPS (P = .002) and patients not meeting ALPS criteria (P < .001). The combination of elevated DNTs and an abnormal in vitro apoptosis functional test was the most useful in identifying all types of ALPS patients; the combination of an abnormal in vitro apoptosis functional test and elevated sFASLs was a predictive marker for ALPS-FAS group identification. Lymphoproliferation, apoptosis functional test, and DNTs are the most sensitive markers; elevated IL-10 and IL-18 are additional indicators for ALPS. The combination of elevated sFASLs and abnormal apoptosis function was the most valuable prognosticator for patients with FAS mutations.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4788-4788
Author(s):  
Nataliya Melnyk ◽  
Jonathan Harrison

Background Acquired coagulopathies are a common problem in Hematology, and are most often due either to medication effect, liver disease, or consumption. Among the uncommon causes of acquired coagulopathy, inhibitory auto-antibodies may develop, either in the setting of autoimmune diseases, in the setting of lymphoproliferative disorders, or as isolated inhibitory immunoglobulins. Uncommonly, the adsorption of coagulation factors from the circulation into the tissues by extracellular deposition of pathologic amyloid results in an acquired factor deficiency, due to clearance of factor from the circulation that exceeds the body's ability to produce factor. When amyoidosis does cause a coagulapathy, it is most often the result of the adsorption of Factor X by the amyloid protein, resulting in an acquired Factor X deficiency. However, there are rare reports of amyloidosis being associated with other factor deficiencies. We report a case of amyloidosis that was associated with a severe bleeding diathesis, with the etiology of the bleeding disorder being due to both acquired Factor V deficiency and concomitant acquired von Willebrand Disease. Case Report A previously healthy 51-year-old gentleman presented to an outside medical center for evaluation and management of recurrent bleeding episodes. The patient had a prior medical history significant only for right ankle trauma in the year 2005, following which he underwent a total of 4 surgical procedures; there was no excessive bleeding complicating the patient's surgeries. He was then in his usual state of health until September, 2012 when he developed onset of severe abdominal pain and was admitted to the outside facility. Following hospitalization for several months at the outside facility, he was admitted to our institution. Physical examination was remarkable for extensive ecchymoses, and for splenomegaly to 18 cm. span by exam, confirmed by imaging. CT scan showed multiple peri-caval and periaortic nodes present up to 1.7 cm in size, with shotty inguinal lymph nodes. A complete blood count showed White blood count 21,600, hemoglobin 8.0 g/dL, hematocrit 24%, platelet count 370,000, Hepatic function studies and renal function studies, as well as electrolytes, were normal on admission. Coagulation studies revealed Prothrombin Time prolonged at 16.8 seconds (normal < 12.7), aPTT prolonged at 44. Mixing patient plasma with equal volume normal plasma corrected both the PT and aPTT. Detailed factor assays showed markedly decreased Factor V activity of 27%; Ristocetin Cofactor activity was markedly decreased at 49%, but von Willebrand antigen was elevated at 213%. Multimer analysis was consistent with Type II vWD (see figure 1). The patient received fresh frozen plasma and Humate P, with transient correction of the bleeding diathesis. This permitted inguinal lymph node biopsy, which documented AL amyloidosis. Extraction of the protein from the lymph node documented AL lambda light chain amyloid (see figure 2). Marrow biopsy documented IgG lambda multiple myeloma. The patient was treated using Bortezumib plus Dexamethasone, and achieved a complete remission, with normalization of the coagulation parameters and factor levels over the following several months. His bleeding diathesis has fully resolved, and Karnofsky performance status improved to 100%. Conclusion Although there are several case reports of acquired von Willebrand disease on the basis of amyloidosis, and several case reports of acquired Factor V deficiency on the basis of amyloidosis, this appears to be the first reported case of both acquired vWD and acquired Factor V deficiency on the basis of amyloidosis. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Rong Yu ◽  
Lv Liu ◽  
Ya-Li Li ◽  
Liang-Liang Fan

Waardenburg syndrome (WS) is a group of rare genetic disorders characterized by hearing loss, changes in coloring of hair, skin, and eyes, and alterations in the shape of the face. Tietz syndrome is another rare disorder which presented similar phenotypes to WS. Patients with Tietz/Waardenburg syndrome often present with pale blue eyes, albino skin, and distinctive hair coloring, such as a patch of white hair or hair that prematurely turns gray. At present, more than six candidate genes are responsible for four types of Waardenburg syndrome and Tietz syndrome. This study is aimed at identifying the pathogenic gene variants in a three-generation Han Chinese family with hearing loss, blue-gray iris, albino skin, and white hair. In order to discover the molecular genetic lesion underlying the disease phenotype, whole exome sequencing in the proband, with Tietz/Waardenburg syndrome phenotypes, of a Han Chinese family from HeBei, China, was conducted. A novel heterozygous c.650G>C/p.Arg217Thr variant in melanocyte inducing transcription factor (MITF) was identified. Sanger sequencing further validated that this mutation existed in three affected individuals and absent in healthy family members. Bioinformatics analysis predicted that this mutation was deleterious. Our study further identified the genetic lesion of the family. Simultaneously, our study may also contribute to genetic counseling, embryonic screening of in vitro fertilized embryos, and prenatal genetic diagnosis of patients with Tietz/Waardenburg syndrome, especially for the proband, unmarried and unpregnant women, to reduce familial transmission in this Han Chinese family.


2021 ◽  
Author(s):  
Karen I Lange ◽  
Sunayna Best ◽  
Sofia Tsiropoulou ◽  
Ian Berry ◽  
Colin A Johnson ◽  
...  

Purpose: A molecular genetic diagnosis is essential for accurate counselling and management of patients with ciliopathies. Uncharacterized missense alleles are often classified as variants of uncertain significance (VUS) and are not clinically useful. In this study, we explore the use of a tractable animal model (C. elegans) for in vivo interpretation of missense VUS alleles of TMEM67, a gene frequently mutated as a cause of ciliopathies. Methods: CRISPR/Cas9 gene editing was used to generate homozygous worm strains carrying TMEM67 patient variants. Quantitative phenotypic assays (dye filling, roaming, chemotaxis) assessed cilia structure and function. Results were validated by genetic complementation assays in a human TMEM67 knock-out hTERT-RPE1 cell line. Results: Quantitative assays in C. elegans distinguished between known benign (Asp359Glu, Thr360Ala) and pathogenic (Glu361Ter, Gln376Pro) variants. Analysis of seven missense VUS alleles predicted two benign (Cys173Arg, Thr176Ile) and four pathogenic variants (Cys170Tyr, His782Arg, Gly786Glu, His790Arg). Results from one VUS (Gly979Arg) were inconclusive in worms, but additional in vitro validation suggested it was likely benign. Conclusion: Efficient genome editing and quantitative functional assays in C. elegans make it a tractable in vivo animal model that allows stratification and rapid, cost-effective interpretation of ciliopathy-associated missense VUS alleles.


1977 ◽  
Author(s):  
Donald I. Feinstein

Twelve patients with an acquired inhibitor of Factor V have been reported thus far in the literature. Of these, only one occurred in a patient with hereditary Factor V deficiency. Six patients received streptomycin in close temporal relationship to the appearance of the inhibitor. Six of the patients had been previously transfused, including four of those who received streptomycin. In nine of the eleven spontaneously occurring inhibitors, major surgery preceded the appearance of the inhibitor. The degree of clinical bleeding in these patients varied. One patient had no bleeding, six patients had mild to moderate bleeding, and four patients had severe bleeding. The inhibitor disappeared in less than eight weeks in seven patients, whereas in one patient it persisted for more than two years. Most of these inhibitors have the physiochemical properties of antibodies. Six of the spontaneous inhibitors appeared to be IgG, whereas in two patients inhibitor activity was found in both IgM and IgG fractions. Three inhibitors have been typed with light chain antisera and all contained both kappa and lambda chains. Plasmas from seven patients with hereditary Factor V deficiency have been tested with three of these inhibitors for inactive factor V antigenic material and none has been detected. In addition, plasma from a patient with hereditary factor V deficiency has been tested with heterologous factor V antibody and no antigenic material has been found. Thus hereditary factor V deficiency probably represents a deficiency of factor V molecules, rather than the synthesis of a defective molecule.


Blood ◽  
2002 ◽  
Vol 99 (8) ◽  
pp. 3063-3065 ◽  
Author(s):  
Iris Schrijver ◽  
Marion A. Koerper ◽  
Carol D. Jones ◽  
James L. Zehnder

Abstract We investigated a family whose proband has a severe bleeding disorder and factor V antigenic and functional levels of 8% and less than 1% of control values, respectively. Molecular analysis of the factor V gene revealed a novel homozygous mutation in the last nucleotide of exon 10. 1701G&gt;T causes activation of a cryptic exonic splice site in exon 10, which encodes part of the factor V heavy chain (A2 domain). This leads to the deletion of 35 nucleotides and results in a frameshift with a premature stop codon at amino acid position 498. The G1701 and corresponding Gln509 are conserved in murine, bovine, and porcine factor V and in human factor VIII. Few factor V deficiency mutations have been identified as yet. Several are present in the heterozygous form in combination with factor V Leiden (Arg506Gln). This is the first reported homozygous splice site mutation in a patient with factor V deficiency.


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