Patient 3: heterozygous pathogenic ATM GV
Patient 3 was seen by dermatology at age two for a temporal lesion which
started to thicken. The lesion was diagnosed as a spitzoid nevus and
observed until the family requested removal. A shave biopsy confirmed
SM. WLE and SLNB were performed with one positive LN. Treatment was
surgery only and patient has been disease-free for three years. Germline
testing identified a maternally inherited ATM pathogenic
GV. Although the ATM variant is silent, experimental
studies have demonstrated a splicing effect that results in skipping of
exon 14.3,4 Cascade testing informed care of the
patient’s mother, who was recommended to initiate breast cancer
surveillance with mammograms with consideration of tomosynthesis and
breast MRI with contrast starting at 40 years old or 5-10 years before
earliest age of breast cancer diagnosis.5