MRX42: Two linkage intervals, one in the pericentromeric region and one in Xq26, and the impact for carrier risk estimation

• Published in: American journal of medical genetics Vol. 107; no. 1; pp. 18 - 25
• Main Authors: Golla, Astrid, Rost, Imma, Jedele, Kerry Baldwin, Albert, Angelika, Murken, Jan, Holinski-Feder, Elke
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01-01-2002; Wiley-Liss
• Subjects: Adult; Biological and medical sciences; Cell Cycle Proteins - genetics; Centromere; Chromosome Mapping; Cytogenetic Analysis; Female; Fragile X Mental Retardation Protein; General aspects. Genetic counseling; Genetic Counseling; Genetic Linkage; Guanine Nucleotide Exchange Factors - genetics; Heterozygote; Humans; Intellectual Disability - genetics; Male; Medical genetics; Medical sciences; Middle Aged; MRX42; Nerve Tissue Proteins - genetics; nonspecific X-linked mental retardation; Pedigree; pericentromeric; Rho Guanine Nucleotide Exchange Factors; Risk Factors; RNA-Binding Proteins; X Chromosome; Xq26; Sex linked character; Linkage; Family study; Estimation; Male; Risk; Developmental disorder; Responsibility; Mental retardation; Genetic disease; Characterization; Prenatal; Gene; Mother; Pedigree; Risk factor; Intellectual deficiency; Genetics; Female; Region; X-Chromosome; Carrier; Complex syndrome; Interval
• ISSN: 0148-7299; 1096-8628
• DOI: 10.1002/ajmg.10027

A nonspecific X‐linked mental retardation (MRX) family is reported with four mild to moderately affected males and no intellectual impairment in their obligate carrier mothers. Linkage analysis obtained the same multipoint lod score of 2.08 for two intervals on the X chromosome already reported to be linked to other MRX and syndromic X‐linked mental retardation (XLMR) families: one pericentromeric and the other at Xq26. Since the responsible gene is not yet characterized, haplotyping is presently the only means available for carrier and prenatal testing for this form of MRX. Carrier risk estimation using pedigree and haplotype data for five females at risk is presented, and the difficulties of prenatal diagnosis given linkage to two different regions is discussed. © 2001 Wiley‐Liss, Inc.