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Novel prothombin mutations in Puerto Rican children
Author(s) -
Ortiz IR,
Lefkowitz JB,
Weller A,
SantiagoBorrero PJ
Publication year - 2002
Publication title -
haemophilia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.213
H-Index - 92
eISSN - 1365-2516
pISSN - 1351-8216
DOI - 10.1046/j.1365-2516.2002.d01-2_1.x
Subject(s) - medicine , proband , pediatrics , bleed , population , mutation , point mutation , gastroenterology , genetics , surgery , gene , biology , environmental health
Prothrombin (FII) deficiency is a rare congenital bleeding disorder. We have identified 8 children (7 families) with this condition, accounting for 6% of the congenital coagulation disorders (excluding VWD), followed at the Puerto Rico Pediatric Hemophilia Treatment Center. The mean age at first significant bleeding episode was 5.9 years, ranging from 9 months to 14 years. The first bleeding symptoms were mostly mucosal, with only one child with a joint bleed. Sex distribution was even, and all but one had family history of a coagulation disorder. FII activity levels ranged from 10% to 27% with a mean FII level of 17.3%. The PT and PTT were slightly abnormal in all, with a mean PT of 14.3 sec and mean PTT of 38.4 sec. DNA sequencing has been done on four patients from three families. One patient was found to be homozygous for a prothrombin mutation previously described in a patient of Puerto Rican origin, Arg‐457→Gln (Prothrombin Denver V). Probands in two families were compound heterozygotes for the Denver V mutation and two novel mutations. One of these, named Prothrombin Puerto Rico I, is a point mutation predicting a Gla‐16→Gln substitution. The other mutation, designated Prothrombin Puerto Rico II, is a five base deletion in Exon XIII resulting in a premature stop codon. FII deficiency is the third most common congenital coagulation factor deficiency in Puerto Rican children, suggesting a higher prevalence in our population. Our studies have identified two novel mutations in the prothrombin genes of these children.