When affected individuals display aggressive or destructive behavior that could harm themselves or others, the antipsychotic medication risperidone may eventually be prescribed. It is recommended that spinal development be monitored regularly by X-ray and physical exams. Echocardiograms are recommended every 5–10 years to assess cardiac function and development. Families are encouraged to receive genetic counseling in order to understand and prepare to provide care for children affected by Coffin–Lowry syndrome. Prognosis
Lifespan may be significantly shortened in males with Coffin–Lowry syndrome. Patients may survive into their late twenties, but generally die young due to cardiac, respiratory, and post-operative complications. The progression of reduced cardiac functioning over time may necessitate surgical procedures to counteract mitral valve dysfunction, congenital heart disease, patent ductus arteriosus, and ventricular hypertrophy. Kyphoscoliosis may worsen over time and contribute to these pathologies. Epidemiology
The prevalence of CLS is uncertain due to the rarity of the disease, but CLS is estimated to affect between 1 in 50,000 and 1 in 100,000 people. Prenatal testing is available to test for CLS of an offspring if a family member has been diagnosed with CLS. History
Coffin–Lowry was first described by Grange S. Coffin (b. 1923) in 1966 and independently by Robert Brian Lowry (b. 1932) in 1971. Dr. Temtamy showed that the cases represented a single syndrome in 1975.In 1972, Peter G. Procopis and B. Turner published a case study on a family of four brothers with Coffin-Lowry Syndrome, with female relatives, specifically sisters, only possessing some mild deformities and abnormalities.
Genetics
Coffin–Lowry syndrome is an X-linked disorder resulting from loss-of-function mutations in the RPS6KA3 gene, which encodes RSK2 (ribosomal S6 kinase 2). Multiple mutations have been identified in RPS6KA3 that can give rise to the disorder, including missense mutations, nonsense mutations, insertions and deletions. Individuals with CLS rarely have affected parents, suggesting that most incidents arise from de novo mutations in the germline. The lack of an inheritance pattern may be due to the fact that affected individuals are unlikely to parent children. In 20–30% of cases, however, there is a family history of disease. In these cases, the disorder is typically inherited from the maternal parent. Because RPS6KA3 is located on the X chromosome, males (who possess only one copy of the X chromosome) display more severe symptoms than females. Affected females usually possess one mutated copy of the RPS6KA3 gene and one wild type copy. Random inactivation of one copy of the X chromosome in females mitigates the impact of possessing a mutant allele. Occasionally females are born with two mutated alleles. In these cases the symptoms are as severe as in males with the disease. Cell physiology
Mutations in the RPS6KA3 gene can result in expression of an RSK2 protein (ribosomal S6 kinase 2) with reduced or absent kinase function. RSK2 is a downstream component of the MAPK (mitogen-activated protein kinase) cascade that is itself a kinase. RSK2 phosphorylates cellular proteins (including histone H3, and CREB), which regulate eukaryotic gene expression.