Co-Occurring Thrombotic Thrombocytopenic Purpura and Autoimmune Hemolytic Anemia in a Child Carrying the Pathogenic SHOC2 c.4A>G (p.Ser2Gly) Variant.

BACKGROUND RASopathies involve mutations in genes that encode proteins participating in the RAS-mitogen-activated protein kinase pathway and are a collection of multisystem disorders that clinically overlap. Variants in the SHOC2 gene have been reported in Noonan-like syndrome, which include distinct facial features, short stature, congenital cardiac defects, developmental delays, bleeding disorders, and loose anagen hair. This report is of a 7-year-old girl with the c.4A>G (p.Ser2Gly) variant of the SHOC2 gene, consistent with Noonan-like syndrome, with loose anagen hair, presenting with thrombotic thrombocytopenic purpura and autoimmune hemolytic anemia. CASE REPORT The child had a medical history of 7 hospitalizations at our institution. At the age of 2 months, she underwent surgical correction for ventricular and atrial septal defects. At the age of 2 years, tonsil and adenoid removal surgery was performed, followed by surgery for otitis media at age 5 years. At 7 years, she was hospitalized for the simultaneous occurrence of thrombotic thrombocytopenic purpura and autoimmune hemolytic anemia. The patient displayed short stature and mild intellectual disability. Notable facial features included sparse hair, mild frontal bossing, and low-set ears. Antinuclear antibody levels demonstrated a significant gradual shift. Through trio whole-exome sequencing, a c.4A>G (p.Ser2Gly) variation in the SHOC2 gene was identified. CONCLUSIONS Given the clinical information and genetic testing results, the patient's condition appeared to closely be a type of RASopathy. This report has highlighted the importance of physical, developmental, and genetic testing in children presenting with dysmorphism, developmental delay, and hematological abnormalities.