Biomaterial Database

Constitutive fragile sites 1p31, 3p14, 6q26, and 16q23 and their use as controls for false-negative results with the fragile(X). 1984

A Daniel, and L Ekblom, and S Phillips

Fragile(X) estimations in fragile(X)-mental retardation hemizygotes or heterozygotes can become falsely negative in stored blood (lymphocytes). This was shown in blood stored (before culture) at 4 degrees C, room temperature (25 degrees C), 37 degrees C, and 39 degrees C for 1-4 days. After storage, blood was cultured in Ham's F10-5% FC serum with 0.1 microM FUdR and scored for fra(X) and the constitutive fragile sites at 3p14 and 6q26. It was found that the proportion of cells expressing the fragile(X) and the 3p14 site varied inversely with the temperature and time of storage. In addition, 50 patients and controls were scored for the three latter sites after routine 72-96-hr culture in F10-0.05 or 0.1 microM FUdR. The 3p14 site was detected in every individual tested in a mean +/- S.D. of 11.3 +/- 3.2% of cells (0.1 microM FUdR). It was found that this site was FUdR dose dependent whereas the 6q26 site was not. The 3p14 (but not the 6q26) site is therefore suitable as a control site for the FUdR effect. It is proposed that repeat studies are necessary when less then 4% 3p14 sites are present in specimens from males referred for fra(X) estimation. Other constitutive fragile sites (eg, 1p31 and 16q23) can also be used.

UI	MeSH Term	Description	Entries
D007231	Infant, Newborn	An infant during the first 28 days after birth.	Neonate,Newborns,Infants, Newborn,Neonates,Newborn,Newborn Infant,Newborn Infants
D008297	Male		Males
D002873	Chromosome Fragility	Susceptibility of chromosomes to breakage leading to translocation; CHROMOSOME INVERSION; SEQUENCE DELETION; or other CHROMOSOME BREAKAGE related aberrations.	Chromosomal Fragility,Fragility, Chromosomal,Fragility, Chromosome
D002874	Chromosome Mapping	Any method used for determining the location of and relative distances between genes on a chromosome.	Gene Mapping,Linkage Mapping,Genome Mapping,Chromosome Mappings,Gene Mappings,Genome Mappings,Linkage Mappings,Mapping, Chromosome,Mapping, Gene,Mapping, Genome,Mapping, Linkage,Mappings, Chromosome,Mappings, Gene,Mappings, Genome,Mappings, Linkage
D002900	Chromosomes, Human, 1-3	The large, metacentric human chromosomes, called group A in the human chromosome classification. This group consists of chromosome pairs 1, 2, and 3.	Chromosomes A,Group A Chromosomes,Chromosome, Group A,Chromosomes, Group A,Group A Chromosome
D002902	Chromosomes, Human, 16-18	The short, submetacentric human chromosomes, called group E in the human chromosome classification. This group consists of chromosome pairs 16, 17, and 18.	Chromosomes E,Group E Chromosomes,Chromosome, Group E,Chromosomes, Group E,E Chromosomes, Group,Group E Chromosome
D002906	Chromosomes, Human, 6-12 and X	The medium-sized, submetacentric human chromosomes, called group C in the human chromosome classification. This group consists of chromosome pairs 6, 7, 8, 9, 10, 11, and 12 and the X chromosome.	Chromosomes C,Group C Chromosomes,Chromosomes, Human, 6-12,Chromosome, Group C,Chromosomes, Group C,Group C Chromosome
D005260	Female		Females
D005600	Fragile X Syndrome	A condition characterized genotypically by mutation of the distal end of the long arm of the X chromosome (at gene loci FRAXA or FRAXE) and phenotypically by cognitive impairment, hyperactivity, SEIZURES, language delay, and enlargement of the ears, head, and testes. INTELLECTUAL DISABILITY occurs in nearly all males and roughly 50% of females with the full mutation of FRAXA. (From Menkes, Textbook of Child Neurology, 5th ed, p226)	FRAXA Syndrome,FRAXE Syndrome,Martin-Bell Syndrome,Fra(X) Syndrome,Fragile X Mental Retardation Syndrome,Fragile X-F Mental Retardation Syndrome,Mar (X) Syndrome,Marker X Syndrome,Mental Retardation, X-Linked, Associated With Fragile Site Fraxe,Mental Retardation, X-Linked, Associated With Marxq28,X-Linked Mental Retardation and Macroorchidism,FRAXA Syndromes,FRAXE Syndromes,Fragile X Syndromes,Marker X Syndromes,Martin Bell Syndrome,Syndrome, FRAXA,Syndrome, FRAXE,Syndrome, Fragile X,Syndrome, Marker X,Syndrome, Martin-Bell,Syndromes, FRAXA,Syndromes, FRAXE,Syndromes, Fragile X,Syndromes, Marker X,X Linked Mental Retardation and Macroorchidism
D005786	Gene Expression Regulation	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.	Gene Action Regulation,Regulation of Gene Expression,Expression Regulation, Gene,Regulation, Gene Action,Regulation, Gene Expression