XLID Genetic Research

GGC has a long and successful history in studying X-linked intellectual disability (XLID).

The JC Self Research Institute, a division of GGC, is renowned as an international resource for scientists and clinicians seeking greater understanding of the diagnosis and causes of XLID, as well as prevention and treatment strategies. Many avenues of XLID research are explored at the Institute, from studying the effects of a single gene mutation, to mapping genes along the X chromosome to developing strategies that help families avoid passing on hereditary diseases.

The goal of scientists at JC Self Research Institute is to reduce the prevalence and impact of genetic disorders such as XLID.

Understanding XLID

An intellectual disability is identified as a condition causing significant limitations in social and behavioral skills and cognitive abilities. It is estimated that up to 3% of the population lives with an intellectual disability (ID). Intellectual disability can be caused by environmental circumstances, but genetic causes, such as chromosomal anomalies and single-gene disorders account for up to 50% of moderate to severe cases.

X-linked ID (XLID) is a group of genetic conditions in which the causative gene mutation is located on the X chromosome. Because males have a single X chromosome, XLID predominantly affects males and is passed through their unaffected carrier mothers. Females with a single X-linked mutation have a 50 percent chance of passing on the mutation to their offspring.

Summary of XLID Maps and Genes (updated December 2017)

New X-linked intellectual disability syndromes, new gene localizations, revised gene localizations, and gene identifications are presented in abbreviated form with appropriate references. 

The linkage limits for XLID syndromes and non-syndromal XLID and the band locations for cloned XLID genes are provided in the accompanying illustrations. Click to download figures as pdfs. A table is also available showing the genes involved in X-linked intellectual disability in order of their discovery. 

  • Figure 1 - Location of the genes for XLID syndromes which have been cloned and mutations demonstrated.
  • Figure 2 - Linkage limits for XLID syndromes which have been mapped (lod score >2), but the genes not yet cloned.
  • Figure 3 - Linkage limits for IDX families which have been mapped (lod score >2), but the genes not yet cloned. The locations of the IDX genes which have been cloned are indicated on the left with solid arrows, genes that cause IDX and IDXS are shown on the right with open arrows.
  • Table - Listing of XLID genes and gene functions chronologically by year of discovery.
Meet the Shenal Family

Meet the Shenal Family

Our daughter, Ryleigh, was diagnosed with a rare chromosomal deletion shortly after she was born in 2010. Since we received her diagnosis, the Greenwood Genetic Center has become part of our family. They made certain that we did not feel alone, and they continue to provide ongoing, compassionate care for our child. The impact they have had on our family and others across the globe everyday is immeasurable. We can't imagine walking this journey without their...

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