Kallmann syndrome-heart disease syndrome is a rare condition that involves problems with sexual development and certain heart defects. People with this condition have a deficiency in gonadotropin-releasing hormone (GnRH) which leads to hypogonadotropic hypogonadism. This means that the body has difficulty producing the hormones needed for sexual development. In addition to the hormonal issues, people may experience a reduced sense of smell (anosmia or hyposmia) because their olfactory bulbs are underdeveloped or absent. They also have complex congenital heart malformations, including conditions such as double-outlet right ventricle, dilated cardiomyopathy, and a right aortic arch. This combination of features makes it a distinct clinical entity from Kallmann syndrome without heart disease involvement.

Common symptoms include signs of hypogonadism such as delayed or absent puberty, and a reduced sense of smell due to abnormal development of the olfactory bulbs. In addition, congenital heart malformations may lead to symptoms related to heart function, which can vary depending on the specific type of cardiac defect present.

The condition is characterized by a deficiency in gonadotropin-releasing hormone (GnRH) leading to hypogonadotropic hypogonadism. The exact genetic causes or risk factors beyond this hormonal deficiency are not detailed in the provided information.