Background and Objectives: Primary amenorrhea is not a disease but a symptom that may result from several quite different causes[NN1] . Common hormonal cause of primary amenorrhea includes constitutional delay, hypothalamic –pituitary dysfunction, chronic systemic disease and absent ovarian function. The aim of this study was to estimate the incidence of the chromosomal abnormality referred for karyotyping in patients with primary amenorrhea in southwest of Iran. Material and Methods: Chromosomal analysis was carried out in 220 such cases that were referred from different parts of the south of Iran. The standard protocol for peripheral blood lymphocyte culture was followed for metaphase chromosome preparation and conventional analysis of G-banded chromosome. Results: The frequency of abnormal karyotypes was 20% in primary amenorrhea. The chromosomal abnormalities can be classified into five main types with or without mosaicism. 1-The most frequent karyotype was X chromosome aneuploidies (10%,n=22) 2-Male karyotype 46, XY was present in 5.5 % (n=12). 3-Structural anomalies of the X chromosome were detected in 3.2% (n=7) . 4-Mosaicism of male chromosome constitution and X chromosome aneuploidy was present in two (0.9%) cases (45XO/46XY). 5-Mosaicism of X chromosome aneuploidy and structural anomalies of X chromosome was found in one (0.45%) case [45, X/46X, i (Xq)]. Conclusion: The present study has emphasized that karyotyping is necessary in evaluation of primary amenorrhea. This study also revealed the incidence of chromosomal abnormalities in women with primary amenorrhea in southwest of Iran is similar to that reported in previous literatures.  [NN1]File Format: PDF/Adobe Acrobat - Quick View by SК Ten - 1990 - Cited by 5 - Related articles Primary amenorrhea is not a disease but a symptom that may result from several quite different causes. These include such conditions as endocrinological ... smj.sma.org.sg/3104/3104a13.pdf - Similar