The APC gene mutation variant c.4348C>T p.(Arg1450) (Frequency: 66% of the 1338 NGS reads) generates a premature stop codon in one of the two FAP cases of DTF that have been studied, one of which is a 10-year-old girl with a neck mass and recurrent abdominal wall mass. The gene discussed is APC; the disease is Familial adenomatous polyposis.