Genetic basis of severe factor XIII deficiency in a large cohort of Indian patients: Identification of fourteen novel mutations

Clinical Profile of Congenital Factor XIII Deficiency in Children

OBJECTIVES

Congenital Factor 13 Deficiency (FXIIID) is a rare bleeding disorder (RBD) of autosomal recessive inheritance, with an incidence of 1 in 3-5 million. The clinical symptomatology, diagnosis, and management of FXIIID are described.

METHODS

A retrospective chart review of children with FXIIID was performed from January 2000 through October 2021 at a tertiary care center in Southern India. The diagnosis was performed by the Urea clot solubility test (UCST) and Factor XIII antigen assay.

RESULTS

Twenty children (representing 16 families) were included. Male: Female ratio was 1.5:1. The median age of symptom onset was 6 mo, and the median age of diagnosis was 1 y, demonstrating a delay in diagnosis. Consanguinity was present in 15 (75%) with 4 children having affected siblings. Clinical symptomatology ranged from mucosal bleeds to intracranial bleeds and hemarthrosis, with many children having a history of prolonged umbilical bleeding in their neonatal period. Fourteen children were on cryoprecipitate prophylaxis. Four children had breakthrough bleeds due to irregular prophylaxis, including one intracranial bleed due to a delay in cryoprecipitate prophylaxis during the covid pandemic.

CONCLUSIONS

Congenital FXIIID presents with a wide range of bleeding manifestations. The high prevalence of consanguinity in Southern India can be a cause of FXIIID's high prevalence in this region. There is a propensity for intracranial bleeding with a significant number having this at first presentation. Regular prophylaxis is required and feasible to prevent potentially fatal bleeds.

Identification of a novel mutation in the factor XIII A subunit in a patient with inherited factor XIII deficiency

Inherited factor XIII (FXIII) deficiency is an extremely rare and under-diagnosed autosomal recessive inherited coagulopathy, which is caused by genetic defects in the F13A1 or F13B gene. More than 200 genetic mutations have been identified since the first case of inherited FXIII deficiency was reported. This study aimed to identify underlying gene mutations in a patient with inherited FXIII deficiency who presented with recurrent intracerebral hemorrhage. Levels of plasma FXIII-A antigen were measured, F13A1 and F13B genes were sequenced, mutation information was analyzed, and the mutated protein structure was predicted using bioinformatics methods. Molecular genetic analysis identified four mutations of FXIII-related genes in the proband, including three previously reported mutations inherited from his parents (c.631G>A, p.Gly210Arg and c.1687G>A, p.Gly562Arg of F13A1 gene and c.344G>A, p.Arg115His of F13B gene) and a novel spontaneous mutation of F13A1 gene (c.2063C>G, p.Ser687Cys). Molecular structural modeling demonstrated that the novel Ser687Cys mutation may cause changes in the spatial structure of FXIII-A and increase its instability. In conclusion, we identified a novel and likely pathogenic mutation of the F13A1 gene, which enriched the gene mutation spectrum of inherited FXIII deficiency. The findings may provide promising targets for diagnosis and treatment of inherited FXIII deficiency.

Genetic Spectrum in F13A1 Detected by Next-Generation Sequencing Among North Indian Patients with FXIII Deficiency

Purpose

The study aimed to explore the molecular defects underlying FXIII deficiency.

Materials and Methods

Sixteen unrelated cases were enrolled based on the indication of the urea clot solubility test and Factor XIII-A antigen levels. Cases were further subjected to targeted next-generation sequencing (custom gene panel: F7, F8, VWF, F9, F13A1, F13B). The pathogenic/likely pathogenic variants were validated by Sanger sequencing in the patients and family members.

Results

Mean age of referral to our center was 27.2 years (8 week-67 years). Consanguinity was found in only one of the 16 cases and 9 cases presented in infancy. The most common symptoms were skin bleeds (69%) and umbilical cord bleed (50%). The clot solubility test was positive in 12, inconclusive in 1, and normal in 3. Mean FXIII-A levels were 15.7 IU/dL (range 0.6 to 49.5 IU/dL). Pathogenic/likely pathogenic variants in F13A1 were found in 11 (69%). Nine cases (82%) were homozygous, and two were compound heterozygous. Total eleven variants were found of which four were missense (c.1226G>A; c.998C>T; c.631G>C; c.2134A>C); three deletion (c.521delG; c.742delA; c.1405_1408delCAAA); two nonsense (c.1112G>A; c.1127G>A) and two splice site (c.1909-1G>C; c.2045G>A). No probably pathogenic variant was found in the F13B.

Conclusion

Inherited FXIII deficiency with bleeding is associated with genetic defects in predominantly the F13A1 gene. A variety of variants were seen in this cohort. A nonsense variant c.1127G>A found in three of our cases seems to be recurrent. This data will contribute to designing functional studies and antenatal testing in affected families.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12288-022-01579-1.

Genetic landscape in coagulation factor XIII associated defects – Advances in coagulation and beyond

Coagulation factor XIII (FXIII) acts as a fine fulcrum in blood plasma that maintains the balance between bleeding and thrombosis by covalently crosslinking the pre-formed fibrin clot into an insoluble one that is resistant to premature fibrinolysis. In plasma, FXIII circulates as a pro-transglutaminase complex composed of the dimeric catalytic FXIII-A encoded by the F13A1 gene and dimeric carrier/regulatory FXIII-B subunits encoded by the F13B gene. Growing evidence accumulated over decades of exhaustive research shows that not only does FXIII play major roles in both pathological extremes of hemostasis i.e. bleeding and thrombosis, but that it is, in fact, a pleiotropic protein with physiological roles beyond coagulation. However, the current FXIII genetic-epidemiological literature is overwhelmingly derived from the bleeding pathology associated with its deficiency. In this article we review the current clinical, functional, and molecular understanding of this fascinating multifaceted protein, especially putting into the same perspective its genetic landscape.

Factor XIII Deficiency and Intracranial Bleed: Surgical Management and Prophylaxis with Cryoprecipitate

Factor XIII (FXIII) deficiency is a rare bleeding disorder with affected patients having high propensity for intracranial hemorrhage. A 12-year-old girl presented with severe headache, limb weakness, and rapidly worsening sensorium over 4 days. Magnetic resonance imaging of the brain and computed tomography (CT) of the head showed intraparenchymal bleed. Patient had normal coagulation profile and abnormal FXIII level. The perioperative management included cryoprecipitate transfusion to bring the FXIII value to 74%. She underwent craniotomy and evacuation of the hematoma. Postoperatively, she received prophylaxis against rebleed with cryoprecipitate. In the absence of FXIII concentrate, correction of FXIII deficiency is possible with cryoprecipitate in emergent situations.

Phenotype and genotype of FXIII deficiency in two unrelated probands: identification of a novel F13A1 large deletion mediated by complex rearrangement

Background

Inherited Factor XIII deficiency (FXIIID) is one of the most severe and under-diagnosed rare bleeding disorders. Only 5 large deletions involving one or more exons in F13A1 have been reported, and lacking of multiplex ligation-dependent probe amplification (MLPA) assay might underestimate the copy number variations (CNVs) in F13A1 and F13B. We had characterized the clinical presentation of two unrelated severe FXIIID probands and explored the pathogenic mechanisms.

Results

Both probands experienced several episodes of fatal bleeding and delayed wound healings prior to diagnosis. FXIII activity was measured by the ammonia release assay, and FXIII-A and FXIII-B antigens were determined by ELISA. All the exons including exon-intron boundaries and promoter regions of F13A1 and F13B were amplified and directly sequenced. Copy number variations (CNVs) of F13A1 and F13B were detected by the CNVplex® method. Breakpoints of the F13A1 large deletion were identified by quantitative primer walking combined long-range PCR (LR-PCR) strategies. Proband 1 was found to have compound heterozygous mutations of a novel small deletion (c.1147del) and a missense mutation p.Arg383Ser. Proband 2 was compound heterozygous for a novel large deletion (g.[77815_112815del;112837_116628del]) and a missense mutation p.Arg716Gly in F13A1. Bioinformatics analysis of the large deletion breakpoints predicted that two fork stalling and template switching and/or microhomology-mediated break-induced replication (FoSTeS/MMBIR) events with two homologies of TCT and C might be responsible for the complex rearrangement. Prophylactic replacement therapy was immediately administered for the two probands upon establishment of the diagnosis.

Conclusions

We detected two type I FXIIID pedigrees and adopted CNVplex® method to detect CNVs of F13A1 and F13B for the first time. A large heterozygous deletion of g.[77815_112815del;112837_116628del] in F13A1, mediated by two FoSTeS/MMBIR events, was identified.

Electronic supplementary material

The online version of this article (10.1186/s13023-019-1144-z) contains supplementary material, which is available to authorized users.

Segmental uniparental disomy as a rare cause of congenital severe factor XIII deficiency in a girl with only one heterozygous carrier parent

Uniparental disomy (UPD) refers to a situation when a person inherits both homologs of a region or complete part of a chromosome from only one parent. Here, we present an unusual case of UPD in congenital severe factor (F) XIII deficiency. A 6-year-old girl experienced cephalhematoma and umbilical bleeding after birth and easy bruising, and postextraction bleeding since early infancy. FXIII activity was 0% [mother 53.7% and father 132.5% (normal 70-140%)] and the FXIII antigen level was 2.5% [mother 38.9% and father 151% (normal 75-155%)]. The washed platelet FXIII activity was 0.1% in the patient (normal 64-144%), suggesting a deficiency of FXIII-A subunit. The FXIII-A subunit genetic analysis detected a homozygous p.Arg382Ser mutation. A similar heterozygous mutation was detected in the mother but surprisingly, not in the father. Kinship was confirmed by a paternity test. To confirm the possibility of UPD, a test using four markers in the vicinity of the F13A1 gene revealed that she inherited duplicate mutations from a heterozygous mutation in her mother, presenting a unique case of unusual maternal segmental UPD in otherwise unexplained congenital (homozygous) severe FXIII deficiency. UPD as a rare cause of autosomal recessive bleeding disorder when only one parent is affected is critical for genetic counseling.

Molecular Basis of Congenital Factor XIII Deficiency in Iran

Factor XIII deficiency (FXIIID) is an extremely rare autosomal recessive disorder that has the highest incidence in Iran. The FXIIID is primarily due to mutations in the FXIII-A gene, most of which are unique. In the current study, we report all identified mutations among Iranian patients. Among 483 patients, 366 (75.8%) were molecularly analyzed; 11 different mutations were observed. Of 11, 8 (72.7%) are missense, whereas the remaining 3 (27.3%) are deletion/insertion. Among these patients, 347 (94.9%) had the unique mutation of c.562T>C and 5 (1.4%) had the c.233G>A mutation. c.1226G>A, c.2111G>A, and c.1142T>A are also common, whereas other mutations, including 3 missense and 3 deletion/insertion, were observed only in single patient. Although, in most cases, FXIII mutations are unique and restricted to a specific family, this differs in Iran where a considerable number of identified mutations, recurrently observed, appear to be due to the high rate of consanguinity.

Blood coagulation factor XIII and factor XIII deficiency

Factor XIII (FXIII) is a multifunctional pro-γ-transglutaminase that, in addition to its well-known role in hemostasis, has a crucial role in angiogenesis, maintenance of pregnancy, wound healing, bone metabolism, and even cardio protection. FXIII deficiency (FXIIID) is a rare bleeding disorder (RBD) with an estimated incidence of one per two million that is accompanied by life-threatening bleeding such as umbilical cord bleeding, recurrent spontaneous miscarriage, and intracranial hemorrhage (ICH). Today, the disease is successfully managed by FXIII concentrate and recombinant FXIII for prophylaxis, management of minor and major bleeding, treatment of ICH, and successful delivery in women with recurrent pregnancy loss. Molecular analysis of patients with FXIIID revealed a wide spectrum of mutations, most frequently missense mutations in the FXIII-A subunit, with a few recurrent mutations observed worldwide. In vitro expression studies revealed that most of the missense mutations cause intracellular instability of the FXIII protein and, subsequently, FXIIID.