Further classes strongly associated with higher tumor risk are the Phosphatase and tensin homolog (PTEN) hamartoma tumor syndromes, the Constitutional mismatch repair deficiency (CMMRD) syndromes, certain types of chromosomal aneuploidies or abnormalities, and the Multiple endocrine neoplasia (MEN) syndromes. The gene discussed is PTEN; the disease is multiple endocrine neoplasia.