Syphilis serology was performed on both parents, yielding the following results: in the mother, we noted RPR reactive at 1:16, reactive screening IgG/IgM, TPHA reactive at 1/2,500, Syphilis-specific IgG 23.42 IU/mL and IgM 3.99 IU/mL (normal ranges: 0–1); in the father, we found RPR reactive at 1:2, reactive screening IgG/IgM, TPHA reactive at 1/2,560, Syphilis-specific IgG 27.48 IU/mL and IgM 1.07 IU/mL (normal ranges: 0–1). Here, CD40LG is linked to syphilis.