Protein C (PROC) gene mutations in two Indian families with purpura fulminans
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LETTER TO THE EDITOR Protein C (PROC) gene mutations in two Indian families with purpura fulminans Navin Pai & Shrimati Shetty & Kanjaksha Ghosh Received: 30 September 2009 / Accepted: 22 December 2009 / Published online: 14 January 2010 # Springer-Verlag 2010 Dear Editor, Protein C is (PC) a vitamin K-dependent coagulation protein that serves a critical role in the regulation of thrombin by inactivation factor V and factor VIII [1]. The clinical manifestation of PC deficiency in neonates is generally disseminated intravascular coagulation and pur- pura fulminans [2]. Severe homozygous PC deficiency with purpura fulminans is usually fatal and occurs with an incidence of approximately one in 500,000 to 750,000 live births worldwide. We report two unrelated Indian patients with severe type 1 protein C deficiency, manifesting as purpura fulminans. Case 1, a 10-day-old neonate born of consanguineous marriage was referred to our laboratory for evaluation of thrombophilia. Additional history revealed that their first child had died under similar circumstances, and both mother and maternal uncle had an episode of superior sagittal sinus thrombosis. The PC antigen and activity levels of the index case were 5% and 7.5% (posttrans- fusion), respectively, while that of the parents were found to range from 60% to 64% (normal range 70– 140%); other thrombophilia markers studied were nor- mal. The CT scan of the brain revealed ischemic damage, and ultrasonography of the retina showed vitreous hemorrhage along with necrotic patches on the left ankle. The child was transfused with fresh frozen plasma (FFP), i.v. heparin supplemented with ceftriaxone. Subse- quently, after the wound healing, the anticoagulation was continued with warfarin (0.2 mg/kg/day). The child died on the 28th day after birth. Case 2 was a 3-day-old neonate, presented with blackish discoloration over skin and scalp, referred to our laboratory for thrombophilia testing. Parents were first degree cousins, and two siblings of the index case had died due to similar clinical manifestations. The index case had normal liver and renal function, and the USG showed bilateral hydroneph- rosis and hydrourectic bladder obstruction and subsequently developed scrotal hematoma. The child was treated with FFP supplemented with enoxaparin, vitamin K injections, linezolid (oxazolidinone class of antibiotic) along with cefotaxime (cephalosporin class). After the lesion was healed, patient was subsequently treated with warfarin (0.2 mg/kg/day). The protein C antigen and activity levels of the index case were found to be 3% and 5%, respectively (posttransfusion), while those of the parents were found to vary between 36% and 42%. The child died on the 27th day after birth. In both the index cases, the basal levels of protein C antigen and activity could not be estimated. Molecular analysis of the PROC gene was carried out by PCR, conformation-sensitive gel electrophoresis (CSGE) [3], and DNA sequencing in the parents and the index cases in both the families. Case 1 showed a homozygous missense mutation in exon 7 of PROC gene, e.g., 6246, G→A (Fig. 1a), which resulted in an amino acid change of highly conserved arginine (positive and hydrophilic) to glutamine (hydrophilic). Gene expression studies of this mutant by Sugahara et al. [4] have shown that this mutation occurred at the vicinity of activation peptide cleavage site N. Pai : S. Shetty (*) : K. Ghosh Department of Haemostasis and Thrombosis, National Institute of Immunohaematology (ICMR), 13th Floor, KEM Hospital, Parel, Mumbai 400 012, India e-mail: [email protected] K. Ghosh e-mail: [email protected] Ann Hematol (2010) 89:835–836 DOI 10.1007/s00277-009-0893-5
Transcript of Protein C (PROC) gene mutations in two Indian families with purpura fulminans
LETTER TO THE EDITOR
Protein C (PROC) gene mutations in two Indian familieswith purpura fulminans
Navin Pai & Shrimati Shetty & Kanjaksha Ghosh
Received: 30 September 2009 /Accepted: 22 December 2009 /Published online: 14 January 2010# Springer-Verlag 2010
Dear Editor,Protein C is (PC) a vitamin K-dependent coagulationprotein that serves a critical role in the regulation ofthrombin by inactivation factor V and factor VIII [1]. Theclinical manifestation of PC deficiency in neonates isgenerally disseminated intravascular coagulation and pur-pura fulminans [2]. Severe homozygous PC deficiency withpurpura fulminans is usually fatal and occurs with anincidence of approximately one in 500,000 to 750,000 livebirths worldwide.
We report two unrelated Indian patients with severe type1 protein C deficiency, manifesting as purpura fulminans.Case 1, a 10-day-old neonate born of consanguineousmarriage was referred to our laboratory for evaluation ofthrombophilia. Additional history revealed that their firstchild had died under similar circumstances, and bothmother and maternal uncle had an episode of superiorsagittal sinus thrombosis. The PC antigen and activitylevels of the index case were 5% and 7.5% (posttrans-fusion), respectively, while that of the parents werefound to range from 60% to 64% (normal range 70–140%); other thrombophilia markers studied were nor-mal. The CT scan of the brain revealed ischemic damage,and ultrasonography of the retina showed vitreoushemorrhage along with necrotic patches on the left
ankle. The child was transfused with fresh frozen plasma(FFP), i.v. heparin supplemented with ceftriaxone. Subse-quently, after the wound healing, the anticoagulation wascontinued with warfarin (0.2 mg/kg/day). The child diedon the 28th day after birth.
Case 2 was a 3-day-old neonate, presented with blackishdiscoloration over skin and scalp, referred to our laboratoryfor thrombophilia testing. Parents were first degree cousins,and two siblings of the index case had died due to similarclinical manifestations. The index case had normal liver andrenal function, and the USG showed bilateral hydroneph-rosis and hydrourectic bladder obstruction and subsequentlydeveloped scrotal hematoma. The child was treated withFFP supplemented with enoxaparin, vitamin K injections,linezolid (oxazolidinone class of antibiotic) along withcefotaxime (cephalosporin class). After the lesion washealed, patient was subsequently treated with warfarin(0.2 mg/kg/day). The protein C antigen and activity levelsof the index case were found to be 3% and 5%, respectively(posttransfusion), while those of the parents were found tovary between 36% and 42%. The child died on the 27th dayafter birth.
In both the index cases, the basal levels of protein Cantigen and activity could not be estimated.
Molecular analysis of the PROC gene was carried out byPCR, conformation-sensitive gel electrophoresis (CSGE)[3], and DNA sequencing in the parents and the index casesin both the families. Case 1 showed a homozygousmissense mutation in exon 7 of PROC gene, e.g., 6246,G→A (Fig. 1a), which resulted in an amino acid change ofhighly conserved arginine (positive and hydrophilic) toglutamine (hydrophilic). Gene expression studies of thismutant by Sugahara et al. [4] have shown that this mutationoccurred at the vicinity of activation peptide cleavage site
N. Pai : S. Shetty (*) :K. GhoshDepartment of Haemostasis and Thrombosis,National Institute of Immunohaematology (ICMR),13th Floor, KEM Hospital, Parel,Mumbai 400 012, Indiae-mail: [email protected]
K. Ghoshe-mail: [email protected]
Ann Hematol (2010) 89:835–836DOI 10.1007/s00277-009-0893-5
by thrombin, and this lead to the protein C deficiency by animpairment of secretion of the respective mutant proteins.Case 2 showed an in-frame deletion in exon 5 of PROCgene in homozygous condition, e.g., 3156, del C (Fig. 1b).A deletion mutation at the same position has been reportedearlier by Poort et al. [5] albeit with a larger segmentdeletion. The parents in both the families were found to beheterozygous carriers of the respective mutations. Both thefamilies were counseled about the possibility of antenataltest in subsequent pregnancies.
In conclusion, we report the characterization of PROCgenemutations in two Indian families with purpura fulminans.PROC gene mutation studies would be a useful tool toscreen potential families with purpura fulminans, especiallyin Asian countries where consanguineous marriages are verycommon.
References
1. Esmon C (2000) The protein C pathway. Crit Care Med 28:44–482. Seligsohn U, Berger A, Abend M, Rubin L, Attias D, Zivelin A,
Rapaport SI (1984) Homozygous protein C deficiency manifestated bymassive venous thrombosis in the newborn. N Eng JMed 310:559–562
3. Ganguly A, Rock MJ, Prockop DJ (1993) Conformation-sensitivegel electrophoresis for rapid detection of single-base differences indouble-stranded PCR products and DNA fragments: evidence forsolvent-induced bends in DNA heteroduplexes. Proc Natl Acad Sci90:10325–10329
4. Sugahara Y, Miura O, Hirosawa S, Aoki N (1994) Compoundheterozygous protein C deficiency caused by two mutations, Arg-178 to Gln and Cys-331 to Arg, leading to impaired secretion ofmutant protein C. Thromb Haemost 72:814–818
5. Poort SR, Pabinger-Fasching I, Mannhalter C, Reitsma PH, BertinaRM (1993) Twelve novel and two recurrent mutations in 14Austrian families with hereditary protein C deficiency. BloodCoagul Fibrinolysis 4:273–280
A
Parents - heterozygous Normal Mutant Index case-homozygous
B
Parents - heterozygous normal mutant Index case-Homozygous
Fig. 1 CSGE profile and thePROC gene mutations detectedin patients with purpura ful-minans. a Case 1 showingaltered mobility pattern in exon7 and the electropherogram ofthe same amplicon showingmutation at 6246, G→A. b Case2 showing altered CSGE profilein exon 5 and the electrophero-gram of the same ampliconshowing an in-frame deletionat 3156, C del
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