A gene for dominant nonspecific X-linked mental retardation is located in Xq28.
Am J Hum Genet
; 60(4): 903-9, 1997 Apr.
Article
en En
| MEDLINE
| ID: mdl-9106537
ABSTRACT
A large family (MRX48) with a nonspecific X-linked mental retardation condition is described. An X-linked semidominant inheritance is suggested by the segregation in three generations of a moderate to severe mental retardation in seven males and by a milder intellectual impairment in two females, without any specific clinical, radiological, or biological feature. Two-point linkage analysis demonstrated significant linkage between the disorder and several markers in Xq28 (maximum LOD score [Zmax] = 2.71 at recombination fraction [theta] = 0); multipoint linkage analyses confirmed the significant linkage with a Zmax of 3.3 at theta = 0, at DXS1684. A recombination event observed with the flanking marker DXS8011 delineates a locus between this marker and the telomere. The approximate length of this locus is 8-9 cM, corresponding to 5.5-6 Mb. In an attempt to explain the variable intellectual impairment in females, we examined X-chromosome inactivation in all females of the family. Inactivation patterns in lymphocytes were random or moderately skewed, and no correlation between the phenotypic status and a specific inactivation pattern was observed. The interval of assignment noted in this family overlaps with five MRX loci previously reported in Xq28.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Aberraciones Cromosómicas Sexuales
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Cromosoma X
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Genes Dominantes
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Ligamiento Genético
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Discapacidad Intelectual
Límite:
Adult
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Aged
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Child, preschool
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Female
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Humans
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Male
País/Región como asunto:
Europa
Idioma:
En
Revista:
Am J Hum Genet
Año:
1997
Tipo del documento:
Article
País de afiliación:
Francia