Genotype phenotype correlation in a pediatric population with antithrombin deficiency.

Inherited antithrombin (AT) deficiency is a rare autosomal dominant disorder, caused by mutations in the AT gene (SERPINC1). Considering that the genotype phenotype relationship in AT deficiency patients remains unclear, especially in pediatric patients, the aim of our study was to evaluate genotype phenotype correlation in a Serbian pediatric population. A retrospective cohort study included 19 children younger than 18 years, from 15 Serbian families, with newly diagnosed AT deficiency. In 21% of the recruited families, mutations affecting exon 4, 5, and 6 of the SERPINC1 gene that causes type I AT deficiency were detected. In the remaining families, the mutation in exon 2 causing type II HBS (AT Budapest 3) was found. Thrombosis events were observed in 1 (33%) of those with type I, 11 (85%) of those with AT Budapest 3 in the homozygous respectively, and 1(33%) in the heterozygous form. Recurrent thrombosis was observed only in AT Budapest 3 in the homozygous form, in 27% during initial treatment of the first thrombotic event. Abdominal venous thrombosis and arterial ischemic stroke, observed in almost half of the children from the group with AT Budapest 3 in the homozygous form, were unprovoked in all cases.Conclusion: Type II HBS (AT Budapest 3) in the homozygous form is a strong risk factor for arterial and venous thrombosis in pediatric patients. What is Known: • Inherited AT deficiency is a rare autosomal dominant disorder, caused by mutations in the SERPINC1gene. • The genotype phenotype correlation in AT deficiency patients remains unclear, especially in pediatric patients. What is New: • The genetic results for our paediatric population predominantly showed the presence of a single specific mutation in exon 2, that causes type II HBS deficiency (AT Budapest 3). • In this group thrombosis mostly occurred as unprovoked, in almost half of them as abdominal thrombosis or stroke with high incidence of recurrent thrombosis, in 27% during initial treatment.

Hemophilia in the newborn without family history--pattern of clinical presentation of three patients.

INTRODUCTION: Hemophilia is the most frequently diagnosed inborn clotting factor deficiency in the newborn. In about half of the cases diagnosis is made during neonatal period. However, due to different clinical presentation comparing to older children, hemophilia in the newborn could be misdiagnosed, especially in the setting of negative family history. CASE REPORT: Clinical features of three newborns with negative family history for hemophilia are described. All three newborns were the first born children with uneventful perinatal history, and they were referred for investigation of convulsions, soft tissue tumorous mass and sepsis, respectively. Prompt diagnosis of underlying bleeding disorder and adequate substitution therapy lead to the good outcome in all three boys. CONCLUSION: Symptoms and signs of hemophilia in the newborn could be at time misleading and contribute to delayed treatment. High index of suspicion on inherited bleeding disorder is warranted in every neonate with intracranial bleeding.