Carney complex is a rare genetic disorder characterized by multiple benign tumors (multiple neoplasia) most often affecting the heart, skin and endocrine system and abnormalities in skin coloring (pigment) resulting in a spotty appearance to the skin of affected areas. Benign tumors of connective tissue (myxomas) are common in individuals with Carney complex and, most often, are found in the heart where they can potentially cause serious, life-threatening complications including stroke, valvular obstruction or heart failure. A wide variety of endocrine abnormalities potentially can occur in the Carney complex affecting a variety of glands. Additional tumors include myxomas affecting the skin and nerve sheath tumors (schwannomas). Skin pigment abnormalities include tiny flat (freckle-like) black or brown spots (multiple lentigines) and small, blue or bluish-black spots (blue nevi). The specific symptoms and severity of the Carney complex can vary greatly from one person to another. In many cases, the Carney complex is due to mutations of the PRKAR1A gene. The mutation can occur randomly for no apparent reason (i.e., new mutation) or be inherited as an autosomal dominant trait.
The Carney complex is a different disorder from the Carney triad. Carney triad encompasses three types of tumors: a gastric stromal sarcoma; functioning extra-adrenal paragangliomas; and pulmonary chondromas. Although these two disorders are completely unrelated, both have sometimes been referred to as Carney syndrome, causing confusion. This report deals solely with the Carney complex.
Normally, every cell has 2 copies of each gene: 1 inherited from the mother and 1 inherited from the father. Carney complex follows an autosomal dominant inheritance pattern, in which a mutation happens in only 1 copy of the gene. This means that a parent with a gene mutation may pass along a copy of their normal gene or a copy of the gene with the mutation. Therefore, a child who has a parent with a mutation has a 50% chance of inheriting that mutation. A brother, sister, or parent of a person who has a mutation also has a 50% chance of having the same mutation. However, if the parents test negative for the mutation (meaning each person’s test results found no mutation), the risk to the siblings significantly decreases but their risk may still be higher than an average risk.
Options exist for people interested in having a child when a prospective parent carries a gene mutation that increases the risk for this hereditary cancer syndrome. Preimplantation genetic diagnosis (PGD) is a medical procedure done in conjunction with in-vitro fertilization (IVF). It allows people who carry a specific known genetic mutation to reduce the likelihood that their children will inherit the condition. A woman’s eggs are removed and fertilized in a laboratory. When the embryos reach a certain size, 1 cell is removed and is tested for the hereditary condition in question. The parents can then choose to transfer embryos which do not have the mutation. PGD has been in use for over 2 decades and has been used for several hereditary cancer predisposition syndromes. However, this is a complex procedure with financial, physical, and emotional factors to consider before starting.