Refractory thrombocytopenia could be a rare initial presentation of Noonan syndrome in newborn infants: a case report and literature review

Table 1 Classification of neonatal thrombocytopenias

Causes	Classification	Condition
Immune-mediated	Neonatal alloimmune	HPA, ABO, HLA antigens systems and Glycoprotein IV
	Maternal autoimmune	ITP, SLE
Infection	Congenital/perinatal infection	Rubella, toxoplasma, CMV, HIV, enteroviruses, Parvovirus B 19, E. coli, GBS, Haemophilus influenzae, herpes simplex
	Postnatally acquired infection	Sepsis
Hypoxia	Placental insufficiency	maternal hypertension, maternal diabetes, IUGR, HELLP syndrome of mother
	Perinatal asphyxia	Drug abuse
Organ dysfunction	Bone marrow replacement	Congenital leukaemia
	Liver	Liver failure
	Spleen	Hypersplenism
Inherited	Normal platelet function	TAR syndrome, ATRUS, CAMT, Fanconi anaemia, MYH9-related, vWD type 2B, TTP, autosomal dominant thrombocytopenia
	Platelet dysfunction	WAS, X-linked macrothrombocytopenia, ChediakeHigashi syndrome, BernardeSoulier syndrome, PariseTrousseau syndrome
Others	Hypercoagulable states	Heparin-induced, DIC, thromboembolism, Kasabache-Merritt syndrome
	Metabolic disease	Proprionic and methylmalonic acidaemia
	Aneuploidy (trisomy 13, 18, 21)
	Necrotising enterocolitis
	Subcutaneous fat necrosis of the newborn

HPA, platelet-specific antigens; HLA, human leucocyte antigen; ITP, idiopathic thrombocytopenic purpura; SLE, systemic lupus erythematosus; CMV, cytomegalovirus; HIV, human immunodeficiency virus; E. coli, Escherichia coli; GBS, group B Streptococcus; NEC, necrotizing entercolitis; IUGR, intrauterine growth restriction; HELLP, hemolysis, elevated liver enzymes and low platelet; TAR, thrombocytopenia with absent radii; ATRUS, amegakaryocytic thrombocytopenia and radio-ulnar synostosis; CAMT, congenital amegakaryocytic thrombocytopenia; vWD, Von Willebrand disease; TTP, Thrombotice-thrombocytopenic purpura; WAS, Wiskotte-Aldrich syndrome; DIC, disseminated intravascular coagulation

ISSN: 1471-2431