HPA-5 typing discrepancy reveals an Ile503Leu substitution in platelet GPIa (α2 integrin).
Vox Sang
; 105(1): 73-6, 2013 Jul.
Article
en En
| MEDLINE
| ID: mdl-23368983
ABSTRACT
BACKGROUND AND OBJECTIVES:
In fetal/neonatal thrombocytopenia, maternal alloimmunization is diagnosed by the identification of the maternal alloantibody and the offending paternal antigen inherited by the foetus/neonate. Today, for practical reasons, most laboratories perform platelet genotyping instead of phenotyping. Here, we report the case of a human platelet antigen (HPA)-5 genotype/phenotype discrepancy observed in a mother who delivered a mildly thrombocytopenic newborn. MATERIALS ANDMETHODS:
Platelet antibody detection and platelet phenotyping were performed using the MAIPA assay; platelet genotypes were determined using BeadChip technology (BioArray), PCR-SSP, PCR-RFLP and sequencing.RESULTS:
Serological investigations revealed the presence of maternal anti-GPIIbIIIa autoantibodies. No alloantibodies were detected. No feto-maternal platelet incompatibility was observed for HPA-1 to -21. The mother and newborn were genotyped as HPA-5aa using BeadChips, but as HPA-5a (weak b) with PCR-SSP and HPA-5ab with PCR-RFLP. Mother's platelets were phenotyped as HPA-5b(+). GPIa exon 13 sequencing confirmed the HPA-5ab genotype of the mother and newborn, and revealed an NM_002203.3c.1594A>C mutation near the HPA-5 polymorphism (5' side), leading to an I503L amino acid change.CONCLUSION:
Feto-maternal alloimmunization was ruled out the neonatal thrombocytopenia probably resulted from maternal anti-GPIIbIIIa autoantibodies. This case highlights that platelet typing should be performed using two different methods to avoid false diagnosis.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Polimorfismo de Longitud del Fragmento de Restricción
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Mutación Missense
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Integrina alfa2
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Genotipo
Tipo de estudio:
Prognostic_studies
Límite:
Adult
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Female
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Humans
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Male
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Newborn
Idioma:
En
Revista:
Vox Sang
Año:
2013
Tipo del documento:
Article
País de afiliación:
Francia