Cytogenetic Study of Patients with Primary Amenorrhea in the Northeast of Iran.

Background & Objective: Primary amenorrhea refers to the absence of menstruation in females of reproductive by age 16 when the development of secondary sexual characteristics is evident (breast development, pubic hair) or by age 14 when there are no secondary sexual characteristics are present. Primary amenorrhea can occur in several quite different reasons. Common hormonal causes of primary amenorrhea include constitutional delay, hypothalamic or pituitary disorders, chronic systemic disease, and primary ovarian insufficiency, some endocrine gland disorders, and other causes. Previous studies suggested that chromosomal abnormality is the second most common cause of amenorrhea. This report aims to measure the prevalence of the chromosomal abnormality in primary amenorrhea (PA) patients in the northeast of Iran.

Methods: Chromosomal study was carried out on 200 patients with clinical features. The standard method for culturing peripheral venous blood lymphocyte was to prepare metaphase chromosomes and perform routine GTG band analysis.

Results: The results revealed that 71% of PA had normal female karyotype (46,XX) and 29% showed different chromosomal abnormalities. The chromosomal abnormalities can be categorized into seven primary groups with or without mosaicism. 1- The most common karyotype was X chromosome aneuploidy (10.5%, n=21), 2- Male karyotype with or without structural abnormality of Y chromosome (5.5 %, n=11), 3- Mosaicism of turner karyotype and structural anomalies of X chromosome (4%, n=8), 4- Structural anomalies of the X chromosome (3.5%, n=7), 5- Mosaicism of turner karyotype and normal karyotype (3%, n=6), 6- Mosaicism of turner karyotype and male karyotype (1.5%, n=3) and 7- Super female karyotype (1%, n=2).

Conclusion: The present study has emphasized that early cytogenetic and timely investigation can be necessary for the evaluation of primary amenorrhea.