Coffin-lowry syndrome was characterised by Coffin (1966) and Lowry (1971).^[1][2][3]

Presentation

Coffin-Lowry syndrome is a condition associated with mental retardation and delayed development, characteristic facial features, and skeletal abnormalities like scoliosis and kyphosis. Males are usually more severely affected than females, but the condition can range from very mild to severe in affected women. The IQ of male patients is generally between 15 and 60. This condition is inherited in an X-linked dominant pattern. There are usually more male than female sufferers because males only have one X chromosome, while females have two.

Coffin-Lowry syndrome was independently described by Dr. Coffin and his associates in 1966 and later described by Dr. Lowry and associates in 1971. Dr. Temtamy showed that the cases represented a single syndrome in 1975.

Causes

Mutations in the RPS6KA3 gene cause Coffin-Lowry syndrome.^[4] This gene is located on the short arm of the X chromosome (Xp22.2). The RPS6KA3 gene makes a protein that is involved with signaling within cells. The protein RSK2 which is encoded by the RPS6KA3 gene is a kinase which phosphorylates some substrates like CREB and histone H3. RSK2 is involved at the distal end of the Ras/MAPK signaling pathway. Researchers believe that the protein helps control the activity of other genes and may play an important role in the central nervous system. Mutations in the RPS6KA3 disturb the function of the protein, but it is not well understood how mutations lead to the signs and symptoms of Coffin-Lowry syndrome. At this time more than 120 mutations have been found¹. Some people with the features of Coffin-Lowry syndrome do not have identified mutations in the RPS6KA3 gene. In these cases, the cause is unknown.

This condition is inherited in an X-linked dominant pattern. A condition is considered X-linked if the gene that causes the disorder is located on the X chromosome (one of the two sex chromosomes). The inheritance is dominant if one copy of the altered gene is sufficient to cause the condition. In most cases, males experience more severe symptoms of the disorder than females. A striking characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.

A majority of boys with Coffin-Lowry syndrome have no history of the condition in their families. These cases are caused by new mutations in the RPS6KA3 gene (de novo mutations). A new mutation means that neither parent has the altered gene, but the affected individual could pass it on to his children.

Prognosis

There is no cure and no standard course of treatment for Coffin-Lowry syndrome. Treatment is symptomatic and supportive, and may include physical and speech therapy and educational services.

Symptoms

Coffin-Lowry syndrome is a severe mental retardation associated with abnormalities of:

Growth

In utero growth is normal but post natal growth is retarded. Patients are sometimes microcephalic.

Cardio-vascular

Cardiac abnormalities affect 15% of the patients.

Skeleton

Progressive kyphoscoliosis affects 1 in 2 patients.

Vision and audition

Auditory abnormalities are frequent and often present. Vision abnormalities are not often present.

References

This article incorporates public domain text from The U.S. National Library of Medicine and the National Institute of Neurological Disorders and Stroke.

fr:Syndrome de Coffin-Lowry pl:Zespó? Coffina-Lowry'ego