<prompt> False regarding Primary hyperparathyroidism isMost cases are sporadicIt is the earliest and most common manifestation of MEN1 syndromeAutosomal recessive inheritance seen in association with MEN syndrome80 cases due to enlargement of a single gland or parathyroid adenoma  <response>: PHPT results from the enlargement of a single gland or parathyroid adenoma in approximately 80 of cases, multiple adenomas or hyperplasia in 15 to 20 of patients, and parathyroid carcinoma in 1 of patients. Most cases of PHPT are sporadic. It also occurs within the spectrum of a number of inherited disorders such as MEN1, MEN2A, isolated familial HPT, and familial HPT with jaw-tumour syndrome. All of these syndromes are inherited in an autosomal dominant fashion. PHPT is the earliest and most common manifestation of MEN1 and develops in 80 to 100 of patients by age 40 years old. 