Introduction Leydig cell hypoplasia (LCH) is an autosomal recessive disease that causes 46, XY sex development disorder. The patients with LCH are usually in the female phenotype and are presented with the complaints of no breast development and primary amenorrhea. In this article, the cases of three siblings who presented with primary amenorrhea and who had LCH were presented. Case A 16-year-old patient with female phenotype is presented with primary amenorrhea. Breast development was at Tanner stage 1, the external genitalia were completely in female phenotype. The karyotype was determined as 46, XY. The hormonal analyses revealed that the testosterone synthesis was insufficient despite the high level of luteinizing hormone (LH). Cortisol, ACTH, 17-Hydroxyprogesterone, and AMH levels were normal. LCH diagnosis was considered in the patient with elevated LH and no testosterone synthesis. A new mutation of homozygous c.161 + 4A > G was detected inLHCGRgene. The same mutation was detected in the patient's two siblings with female phenotype and 46, XY karyotype. Conclusion In patients presenting with primary amenorrhea and karyotype 46, XY, there is no testosterone synthesis and if there is LH elevation, LCH should be considered. We found a novel variant in theLHCGRgene in three siblings with karyotype 46, XY and female phenotype.