Furthermore, FIHP may be an allelic variant of disorders such as MEN1 and for practical purposes individuals with FIHP harbouring MEN1 mutations should be followed up and monitored as per the guidelines for MEN1 (similarly if patients with FIHP have CDC73 mutations, clinical follow up should follow those recommended for HPT-JT). The gene discussed is MEN1; the disease is familial isolated hyperparathyroidism.