Additional neuromuscular features include sleep apnea, muscular spasticity, progressive loss of muscle strength and tone leading to paraplegia or partial paralysis.

Some patients experience stimulus-induced drop attacks (SIDAs, temporary paralytic episodes without loss of consciousness), triggered by unpredictable environmental stimuli (touch, scents, sounds, etc.).

[citation needed] 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).

Individuals with CLS rarely have affected parents, suggesting that most incidents arise from de novo mutations in the germline.

The most common mutation in RPS6KA3 is an early stop codon that fails to produce a functional protein, indicating that disease etiology most likely arises from loss-of-function effects.

RSK2 is highly expressed in the brain, specifically in the neocortex, hippocampus, and Purkinje cells, all of which are involved in cognitive function and behavior.

Behavioral symptoms include aggression and depression, but these may be secondary to the emotional consequences of significant physical disabilities associated with the disorder.

[citation needed] Symptoms table: X-ray and neuroimaging studies may be helpful in confirming a diagnosis of Coffin–Lowry syndrome.

Decreased ribosomal S6 kinase activity in cultured fibroblast or transformed lymphoblast cells from a male indicates Coffin–Lowry syndrome.

[citation needed] Molecular genetic testing on a blood specimen or cells from a cheek swab is available to identify mutations in the RSK2 gene.

When affected individuals display aggressive or destructive behavior that could harm themselves or others, the antipsychotic medication risperidone may eventually be prescribed.

Families are encouraged to receive genetic counseling in order to understand and prepare to provide care for children affected by 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.

[citation needed] 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.

[9] In 1975, Samia Temtamy reported eight patients from three different families displaying symptoms of Coffin-Lowry Syndrome, suggesting that the disorder is more common than believed and often goes underdiagnosed.

On the basis of these reports, AG Hunter, Simone Gilgenkrantz, and ID Young established Coffin-Lowry Syndrome as a novel medical diagnosis and named it for the two doctors to originally describe its clinical symptoms.

The mission of the Foundation is to provide informational links, resources, and databases to families and patients dealing with the disease and enables them to communicate with one another.

Families and patients can share their experiences and retrieve advice on the foundation's online site as well as locate helpful services, telephone support, and day-to-day news on medical progress into understanding and treating those affected by Coffin-Lowry Syndrome.