The FGFR3 gene provides instructions for making a protein that is involved in the development and maintenance of bone and brain tissue. This mutation causes the FGFR3 protein to be overly active, which interferes with normal bone growth and allows the bones of the skull to fuse before they should.As stated by researchers at the University of Washington, Muenke syndrome is inherited in an autosomal dominant manner with incomplete penetrance and variable expressivity.”  Prenatal diagnosis for pregnancies at increased risk is possible if the defining mutation has been identified in the family (Agochukwu et.al. 2006). According to the article Craniosynostosis: Molecular Genetics, penetrance is higher in females (87%) than in males (76%). Muenke syndrome is estimated to account for 25%-30% of all genetic causes of craniosynostosis according to the Journal of Anatomy. Diagnosis
The diagnosis of Muenke syndrome is suspected bases on abnormal skull shape and a diagnosis of coronal craniosynostosis. In 2006, Agochukwu and her colleagues concluded that “A distinct Muenke syndrome phenotype includes: uni or bilateral coronal synostosis, midface hypoplasia, broad toes, and brachydactyly.”  Due to phenotypic overlap and/or mild phenotypes, clinical differentiation of this syndrome may be difficult. The suspected diagnosis is confirmed by a blood test to check for gene mutation. To establish the extent of disease in an individual diagnosed with Muenke syndrome, various evaluations are recommended. Treatment
The treatment of Muenke syndrome is focused on the correction of the abnormal skull shape and mirrors the treatment of coronal craniosynostosis.
XXY males have a ~15-fold higher risk of developing breast cancer than typical, but still lower than that of females. People with the condition have a nearly normal life expectancy.Klinefelter syndrome is one of the most common chromosomal disorders, occurring in one to two per 1,000 live male births. It is named after American endocrinologist Harry Klinefelter, who identified the condition in the 1940s. In 1956, the extra X chromosome was identified as the cause. Mice can also have the XXY syndrome, making them a useful research model. Signs and symptoms
The primary features are infertility and small, poorly functioning testicles. Often, symptoms may be subtle and many people do not realize they are affected. Sometimes, symptoms are more prominent and may include weaker muscles, greater height, poor coordination, less body hair, breast growth, and low libido. Often, these symptoms are noticed only at puberty. Prenatal
An estimated 60% of fetuses with Klinefelter syndrome end in miscarriage. Physical
As babies and children, XXY males may have weaker muscles and reduced strength. As they grow older, they tend to become taller than average. They may have less muscle control and coordination than other boys of their age.During puberty, the physical traits of the syndrome become more evident; because these boys do not produce as much testosterone as other boys, they have a less muscular body, less facial and body hair, and broader hips.