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Genetic and Rare Diseases Information Center (GARD)

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Lubs X-linked mental retardation syndrome

Other Names for this Disease
  • MECP2 duplication syndrome
  • Mental retardation, X-linked, Lubs type
  • XLMR syndrome, Lubs type
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Your Question

My teenage son has been diagnosed with Lubs X-linked mental retardation.  What can you tell me about this condition?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is Lubs X-linked mental retardation syndrome?

Lubs X-linked mental retardation is a genetic condition first described in 1999 by Lubs et al. The condition  is associated with severe mental retardation, infantile hypotonia (low muscle tone), recurrent respiratory infection, absence of speech development, progressive neurological problems (such as seizures and spasticity), and mild facial abnormalities. [1]
Last updated: 12/5/2008

What are the signs and symptoms of Lub X-linked mental retardation? Can the symptoms vary?

Symptoms of Lubs X-linked mental retardation vary from patient to patient, including within the same family.  However, the symptoms that have been observed include severe mental retardation, facial hypotoniaspasticitymicrocephaly, absent or limited speech, limited or absence of walking, seizures, and severe respiratory infections. [2]
Last updated: 6/17/2008

What prognosis is associated with Lubs X-linked mental retardation?

Because symptoms vary from patient to patient, prognosis also varies from person to person. Based on the few documented cases in the medical literature, death typically occurs before the age of 25 years.  However, there are cases in which patients have lived past the age of 25 years. [2]
Last updated: 6/17/2008

What treatment is available for Lubs X-linked mental retardation?

Treatment is individually tailored and is based on the patient's symptoms. 
Last updated: 6/17/2008

What causes Lub X-linked mental retardation?

Lub X-linked mental retardation is caused by microduplications (very small duplication) of chromosome X at Xq28.  The microduplication  consistently includes the MECP2 gene and occasionally encompasses the L1CAM gene. The MECP2 gene has been implicated in a number of other conditions including Rett syndrome. [3]
Last updated: 6/17/2008

How is Lubs X-linked mental retardation inherited?

Lubs X-linked mental retardation is inherited in an X-linked fashion, specifically in a X-linked recessive manner.
Last updated: 6/17/2008

  • Friez MJ, Jones JR, Clarkson K, Lubs H, Abuelo D, Blaymore Bier J, et al. Pediatrics. 6 December 2006; Accessed 6/16/2008.
  • Van Esch H, Bauters M, Igantius J, Jansen M, Raynaud M, Hollanders K et al. Duplication of the MECP2 Region Is a Frequent Cause of Severe Mental Retardation and Progressive Neurological Symptoms in Males. Am. J. Hum. Genet. 2005;
  • MECP2 - methyl CpG binding protein 2. Genetics Home Reference. June 6, 2008; Accessed 6/16/2008.