Any deviation from the normal range of the antimullerian hormone, a peptide produced by the granulosa cells of follicles. Anti-Mullerian hormone (AMH), also known as Mullerian inhibiting substance, is produced by the granulosa cells of small antral follicles of the ovary. AMH has an inhibiting role in the ovary, contributing to follicular arrest. AMH levels in women are low until the age of 8, rise rapidly until puberty and decline steadily from the age of 25 until menopause, when AMH production ceases. [PMID:22693172]