ABSTRACT Morphological variations due to heterochromatic DNA of the secondary constriction re¬gion (qh) of human chromosome 1 are considered normal. The presence of a G-negative band within the qh region of chromosome 1 has been considered as a rare or unusual variant. The aim of the present study was investigated the role of G-negative band that embedded within the secondary constriction region of chromosome 1 in two cases. Both cases were unrelated and two different family. First family history was three postna¬tal loses-one stillborn and second family had three recurrent abortions. There were no risk factors for fetal losses. Clinical assessment and cytogenetic studies were evaluated. Chromosomal analysis was performed with conventional methods from lymphocytes and karyotyped using G and C banding techniques. Male in the first family (case I) was 46,XY,1qh G-negative band in all metaphases and his wife was normal 46, XX chromo¬some structure. Female in the second family (case II) was 46,XX,1qh G-negative band and her husband was normal 46, XY chromosome. Both cases were phenotypicaly nor¬mal and they have one healthy child. We presented that those families for interesting although clinical consequences of heterochromatic variants remain obscure. Our study is important by virtue a rare study to investigate relationship between fetal loses and G-negative band in chromosome1qh. J. Exp. Clin. Med., 2011; 28:117-119