Fragile X-Linked Mental Retardation
American journal of diseases of childrenPublished 1 May 1982
Nancy J. Carpenter
Citations77
Generate an AI Snapshot to get a quick, structured summary of this paper.
Study Snapshot
ObjectiveStudy objective
MethodsResearch methodology
PopulationPopulation studied
Sample sizeSample sizes
OutcomesStudy outcomes here
ResultsStudy results comes here
LimitationsResearch study limitations comes here
A concise AI-generated summary of the paper will appear here once you click Generate AI Snapshot.
Abstract
Fragile X-linked mental retardation is a recently described entity that includes a chromosomal fragile site at Xq28 and macro-orchidism. We studied 50 institutionalized males and 15 noninstitutionalized males and found six (9.2%) with this disorder. Their clinical findings include enlarged testicular volumes, low IQs (30 to 40), perseverative speech patterns, and characteristic facial features, including prominent supraorbital ridges, prognathism, and large ears. We recommend cytogenetic studies for both males and females with mental retardation of unknown origin in order to establish early diagnoses and to extend proper genetic counseling to the affected families.
Keywords
Biochemistry, Genetics and Molecular Biology
Columbia Academic Commons (Columbia University)Language development and language disorders
782 Citations1978Lois Bloom, Margaret Lahey
PubMedA marker X chromosome.
612 Citations1969Herbert A. Lubs
The markerX chromosome described in this paper offers an additional mechanism by which the expression of the effects of a chromosomal variant may vary from generation to generation or individual to individual and permits several basic observations about the behavior and identification of the human X chromosome.
ScienceFragile Sites on Human Chromosomes: Demonstration of Their Dependence on the Type of Tissue Culture Medium
525 Citations1977Grant R. Sutherland
The observation of heritable fragile sites on human chromosomes prepared for lymphocyte cultures has been shown to depend on the type of tissue culture medium in which the lymphocytes are grown.
PubMedHeritable fragile sites on human chromosomes I. Factors affecting expression in lymphocyte culture.
488 Citations1979G.R. Sutherland
There is a correlation between frequency of expression of the sites and pH of the culture medium for the sites on 2q, 10q and Xq, and a definition and classification of fragile sites is proposed.
The Journal of PediatricsX-linked mental retardation, macro-orchidism, and the Xq27 fragile site
248 Citations1980Gillian Turner, Art Daniel +1 more
The 25 affected males with macro-orchidism and Xq27 fra had some minor clinical features in common: there was an increase in birth weight, high forehead, prognathism, pale irides, big ears, and an increased head circumference in infancy and childhood which did not persist into adult life.
New England Journal of MedicineHeterozygous Expression of X-Linked Mental Retardation and X-Chromosome Marker Fra(X)(Q27)
181 Citations1980Gillian Turner, Ross Brookwell +3 more
Journal of Medical GeneticsFamilial X-linked mental retardation with an X chromosome abnormality.
175 Citations1977John F. Harvey, C. Judge +1 more
An X-linked pattern of transmission observed in four families with familial mental retardation in several generations was associated with a probable secondary constriction at the distal end of the q arms of the X chromosome.
Human GeneticsConstitutional chromosomal breakage
147 Citations1976F Giraud, Ségolène Aymé +2 more
There were 18 individuals found to have a constitutional chromosome fragility causing an increase in break frequency, and the six constitutional chromosomal fragilities of the X chromosome had in common the association of mental deficiency, delayed speech, and large malformed ears.
Human GeneticsInherited congenital normofunctional testicular hyperplasia and mental deficiency
133 Citations1976J. M. Cant�, H.E. Scaglia +5 more
Four 46,XY siblings with congenital bilateral megalorchidia, macrogenitosomia, and severe mental deficiency were investigated and demonstrated the existence of normofunctional testicular hyperplasia.
Human GeneticsX-Linked mental retardation with macro-orchidism and the fragile site at Xq27 or 28
114 Citations1979G.R. Sutherland, P. L. C. Ashforth
Data are presented suggesting that the form of X-linked mental retardation with macro-orchidism and the form associated with a fragile site at Xq27 or 28 are the same entity.
Journal of Medical GeneticsX-linked mental retardation associated with macro-orchidism.
109 Citations1975Gillian Turner, Creswell J Eastman +4 more
Two families are described with an X-linked form of mental retardation in whom the affected males were found to have bilateral enlargement of the testes and no conclusive evidence of any endocrine disturbance was found.
Human GeneticsHeritable fragile sites on human chromosomes
97 Citations1979G.R. Sutherland
It is concluded that using present methods, cytogenetic detection of carriers is fairly reliable in females aged less than 20–25 years but unreliable in older females.
PubMedFamilial X-linked mental retardation, verbal disability, and marker X chromosomes.
88 Citations1979PatriciaN. Howard-Peebles, Gayle R. Stoddard +1 more
Results indicate variation of culture conditions can effect the frequency of the marker X and a generalized language disability was found which tended to concentrate in the areas of auditory reception, auditory sequential memory, visual closure and grammatic closure.
American Journal of Medical GeneticsSignificance of phenotypic and chromosomal abnormalities in X‐linked mental retardation (Martin‐Bell or Renpenning syndrome)
79 Citations1980Mark T. Jennings, Judith G. Hall +2 more
Telomeric structural changes similar to the mar(X) (qter) formation were found on certain autosomes, notably, chromosome 6 in some of the affected males, potential and obligate carrier females, and in both related and unrelated normal males.
American Journal of Medical GeneticsNonspecific X‐linked mental retardation I: A review with information from 24 new families
70 Citations1980Diana S. Herbst, John M. Optiz
A great degree of variability was apparent in the mental abilities of affected males, and consideration is given to whether this type of mental retardation is due to X-linked recessive or autosomal dominant sex-limited genes.
Human GeneticsX-linked mental retardation with macro-orchidism and marker X chromosomes
67 Citations1979Patricia N. Howard‐Peebles, Gayle R. Stoddard
A family with X-linked mental retardation and a marker X chromosome was ascertained by the presence of macro-orchidism in the three institutionalized probands by revealing a generalized language disability with commonly occurring articulation errors.
Human GeneticsExpression in fibroblast culture of the satellited-X chromosome associated with familial sex-linked mental retardation
62 Citations1980P B Jacky, F. J. Dill
The satellited-X chromosome previously shown in lymphocyte culture to be associated with certain types of sex-linked mental retardation has, for the first time, been demonstrated in cultured skin fibroblasts and lymphocytes from two affected males and an obligate carrier female.
Human GeneticsFurther delineation of X-linked mental retardation
58 Citations1981Diana S. Herbst, Henry G. Dunn +3 more
It is suggested that there is a type of X-linkedmental retardation with many phenotypic features of marker-X mental retardation but without expression of the X chromosome fragile site.
JAMAX-Linked Mental Deficiency Megalotestes Syndrome
56 Citations1977Rogelio H.A. Ruvalcaba
Members of two kindreds had mental deficiency and megalotestes and increased testicular size, which suggests an X-linked recessive trait or autosomal-dominant trait with male sex limitation.
American Journal of Medical GeneticsThe X‐linked syndrome of macroorchidism and mental retardation: Further observations
55 Citations1978Peter Bowen, B. Biederman +2 more
Six males with the syndrome of macroorchidism and mental retardation are reported, inherited as though X-linked, or possibly autosomal dominant male-limited, and there is no evidence of gonadal dysfunction.
American Journal of Medical GeneticsFragile sites in human chromosomes II: Demonstration of the fragile site Xq27 in carriers of X‐linked mental retardation
44 Citations1980Patricia N. Howard‐Peebles, John M. Optiz
It is suggested that there are two types of families in regard to fragile Xq expression in carrier females, one of which shows no apparent phenotypic effect in the female and the demonstration on the fragileXq becomes more difficult with increasing age, whereas the second type is associated with some phenotypesic effect (ie, reduction in mental ability), and the fragile XQ can be demonstrated regardless of age.
Clinical GeneticsFamilial X‐linked mental retardation with a marker X chromosome and its relationship to macro‐orchidism
39 Citations1980Patricia N. Howard‐Peebles, Gayle R. Stoddard
Data are presented suggesting that actual measurements are required for accurate evaluation of testicular size, and one family from the literature does not support the hypothesis that X‐linked mental retardation with macro‐orchidism and the form associated with a marker X chromosome are the Same entity.
American Journal of Medical GeneticsX‐linked mental retardation with macro‐orchidism and marker‐X chromosomes
34 Citations1980Renée H. Martin, Ching‐Shwun Lin +3 more
The family of 2 men with X-linked mental retardation was investigated for the presence of the markers-X chromosome and macro-orchidism and it appears that there is no preferential inactivation of the marker-X in this woman.
Clinical GeneticsFragile sites in human chromosomes I The effect of methionine on the Xq fragile site
27 Citations1981Patricia N. Howard‐Peebles, Johnny C. Pryor
The Xq fragile site found in males having non‐specific X‐linked mental retardation was studied by varying the chemical and physical parameters of leukocyte cultures and it was indicated that methionine does not function as a stabilizing factor for the fragile site on Xq.