[Thrombotic thrombocytopenic purpura in a newborn]

Novel ADAMTS13 mutation in a family with three recurrent neonatal deaths: a case report and literature review

BACKGROUND

Upshaw-Schulman syndrome (USS) is rare, autosomal recessive, hereditary thrombotic thrombocytopenic purpura (TTP) caused by variants in a disintegrin-like and metalloprotease with thrombospondin type 1 motif (ADAMTS13). USS has a heterogeneous clinical course, and most symptoms overlap with other diseases. Early diagnosis may have important implications for the patients. We found novel ADAMTS13 mutation and explored the clinical features and prognosis of newborn-onset USS to increase awareness of the disease.

CASE DESCRIPTION

The same, non-consanguineous couple had three unexplained neonatal deaths. The symptoms of the three infants were mainly severe jaundice, anemia and thrombocytopenia after birth, which was consistent with the reported USS symptoms of neonates and died rapidly suddenly in the during rescue efforts. By using whole-exome sequencing (WES) for the study family, we found a novel heterozygous compound in ADAMTS13 (c.1187 (exon10) G>A (p.C396Y)/c.1595 (exon14) G>T (p.C532F)) that was carried by the three newborns originating from father and mother respectively. We reviewed nine published studies of newborn-onset USS and compared our cases for clinical symptoms and laboratory testing. All nine published cases were diagnosed by ADAMTS13 activity; in seven cases gene mutation analysis was performed and eight cases were still alive at the time of publication.

CONCLUSIONS

The case has added clinicians' awareness of the diagnosis and treatment of USS. A novel rare mutation in ADAMTS13 broadens the spectrum of genetic causes of this rare disorder and expands the phenotypic spectrum.

Clinical Features and Gene Mutation Analysis of Congenital Thrombotic Thrombocytopenic Purpura in Neonates

Congenital thrombotic thrombocytopenic purpura (TTP) is a rare hereditary disease with a high mortality rate; however, improved patient survival is possible with prompt diagnosis and treatment. The clinical features and mutation sites of a disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13) in congenital TTP were analyzed in a neonate with suspected congenital TTP. High-throughput sequencing, polymerase chain reaction, and Sanger sequencing were utilized for screening of genes related to thrombocytopenic diseases and ADAMTS13 gene mutation testing on blood samples from the neonate and the parents. Domestic and foreign literature reporting the clinical features and variants of ADAMTS13 in neonates with congenital TTP were retrieved, compared, and analyzed. The patient in this case was a girl who had been born for 1 h and admitted to the hospital due to "dyspnea for 1 h." Routine blood tests on admission revealed profound thrombocytopenia. She quickly developed symptoms of systemic hemorrhage and eventually died. The neonate had two older sisters who had died of idiopathic thrombocytopenia and hemorrhage within 24 h of birth. Genetic testing showed that the neonate harbored a compound heterozygous mutation in ADAMTS13, c.1187G>A/c.1595G>T, which is a novel variant. Of the 12 cases (1 case in China and 11 cases in other countries) of congenital TTP in neonates that have been reported globally, ADAMTS13 mutation analysis was only performed in eight neonates. Common clinical manifestations included dyspnea of unknown etiology, bruising, jaundice, hemorrhage, and thrombocytopenia. Hence, the current case contributes to our understanding of the clinical manifestations and types of variants in neonates with congenital TTP. Our results demonstrate the efficacy of high-throughput sequencing technology in genetic testing of neonates suspected with congenital TTP and have revealed a novel compound missense mutation in ADAMTS13 that has not been reported in China or elsewhere.

Congenital Thrombotic Thrombocytopenic Purpura: Atypical Presentation and New ADAMTS 13 Mutation in a Tunisian Child

Background

Congenital deficiency of ADAMTS13 is characterized by systemic platelet clumping, hemolytic anemia and multiorgan failure. Although, more than 100 mutations have been reported, atypical clinical presentation may be involved in diagnostic difficulties.

Case report

A 2 year old Tunisian child presented with chronic thrombopenic purpura which failed to respond to corticosteroids. Hemolytic anemia with schistocytes, occurred ten months later, with no previous history of diarrhea or any neurological abnormality. Renal function and coagulation screening tests were normal. The count of platelet improved after fresh frozen infusion (FFP). Extensive investigations revealed a severe deficiency of ADAMTS 13 activity (level< 5%). Gene sequencing identified mutation in exon 18 of ADAMTS 13 gene. Prophylactic regimen with regular infusions of FFP was associated to favorable outcome.

Conclusion

Early ADAMTS 13 activity testing and gene sequencing associated to precocious plasmatherapy are recommended to reduce morbidity and mortality of congenital TTP.