Systemic lupus erythematosus in a patient with Noonan syndrome-like disorder with loose anagen hair 1: More than a chance association.

Systemic lupus erythematosus (SLE) has been reported among patients with RASopathy. Five patients have been reported: three with SHOC2 variants, one with a PTPN11 variant, and one with a KRAS variant. SHOC2 variant might represent a relatively common predisposing factor for SLE among the RASopathy genes. However, the clinical details were only reported for two patients, while information on the remaining patient appeared only in a tabular format with minimal clinical description. Here, we report a patient with a SHOC2 variant and SLE. The proband was a 28-year-old male patient with intellectual disabilities, a short stature, dysmorphic facial features, and thin hair. He developed hypertrophic cardiomyopathy and afebrile generalized seizures at the ages of 7 and 18 years, respectively. At the age of 24 years, he presented with a 3-day history of intermittent fever accompanied by right chest pain and a malar butterfly rash. He fulfilled both the American College of Rheumatology (ACR) criteria and the Systemic Lupus International Collaborating Clinics (SLICC) criteria for SLE and was successfully treated with prednisolone. Medical exome sequencing identified a de novo SHOC2 variant (c.4A > G, p.S2G). The present report of a second patient who fulfills both the ACR criteria and the SLICC criteria of SLE. We suggest that the association between SHOC2 variant and SLE represents more than a chance association. In the event of fever of unknown origin in patients with constitutional SHOC2 pathogenic variant, SLE should be suspected.