ABSTRACT
Background: In the search of the major genes responsible for the genetic etiology of Nonsyndromic Cleft Lip and Palate (NSCLP), an association study between this malformation and four molecular markers, F13A1 and EDN1 (6p), D17S579 (17q) and BCL3 (19q), was done. Aim: To determine, in a Chilean population, the presence of NSCLP susceptibility regions, as proposed for Caucasian populations in the 6p, 17q and 19q chromosomal regions. Material and Methods: A sample of unrelated NSCLP patients, that belonged to Simplex (Sx) and Multiplex (Mx) families, was analyzed. Blood donors were used as a control group (Co). The DNA of the four markers was amplified by means of PCR, their products analyzed by PAGE denaturants and visualized by silver staining. Statistical analysis was performed using c2 log ratio. Results: Allele frequency distribution of D17S579 was significantly different in all patients with NSCLP and their subgroups, when compared to control subjects. Significant differences in EDN1 frecuency were observed between the total groups of NSCLP patients and those pertaining to the Mx subgroup, when compared to controls. Differences in F13A1 distribution were only observed between NSCLP-Mx patients and controls. There was a slight difference in BCL3 distribution, between the total sample of NSCLP patients and controls. Conclusions: Our results support the hypothesis of the existence of cleft susceptibility regions in 6p and 17q. The small significance of BCL3, suggests that ethnicity can influence the interactions between involved genes
Subject(s)
Humans , Male , Female , Phenotype , Cleft Lip , Cleft Palate , Microsatellite Repeats/genetics , Alleles , Gene FrequencyABSTRACT
Background: Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common craniofacial defect. Association studies have suggested that a cleftinglocus is located on chromosome 4q at or near two microsatellite markers D4S175 and D4S192. Aim: To test the hypothesis on the possible presence of a clefting locus on chromosome 4q. Material and methods: We carried out an association study on a sample of unrelated NSCLP patients, of their unaffected relatives and in controls. Both probands and relatives were further analyzed depending if they originated from simplex or multiplex families. DNA was analyzed with two PCR markers close to the putative NSCLP locus, dinucleotide repeats D4S175 and D4S192. PCR products were resolved by PAGE and visualized by silver staining. Statistical analysis was performed by means of c2 log ratio. Results: Significant differences between NSCLP and controls were observed when comparing the allele frequency distribution of D4S192 both in the total sample as well as in NSCLP-multiplex and simplex cases. No significant differences for D4S175 were observed in any of the comparisons. Unaffected relatives showed significant differences with controls both for D4S175 and D4S192. Conclusions: Our results support the hypothesis that a NSCLP locus maps on chromosome 4q close to the microsatellite marker D4S192. No differences were observed between NSCLP multiplex and simplex cases versus controls, implying that they do not represent different etiologic entities. The results of the present and previous studies in the same group of patients support the hypothesis that several major interacting genes participate in the etiology of NSCLP
Subject(s)
Humans , Male , Female , Adult , Cleft Lip/genetics , Cleft Palate/genetics , Microsatellite Repeats/genetics , Phenotype , Case-Control Studies , Gene Frequency/genetics , Gene Amplification/methodsABSTRACT
Background: Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common craniofacial developmental defect. Association studies have suggested that a clefting locus is located on chromosome 6p at or near two possible loci, Factor 13A (FI3A) in the region 6p 25-24 and HLA at 6p 21.3. Aim. To test the hypothesis on the possible presence of a major gene on chromosome 6p associated with NSCLP. Patients and methods: We carried out an association study on a sample of unrelated NSCLP patients from multiplex (Mx) and simplex (Sx) families, of their unaffected relatives and in control individuals. DNA was analyzed with three PCR markers close to the putative NSCLP locus, dinucleotide repeats at loci D6S89, D6S109 and D6S105. PCR products were resolved by PAGE and visualized by silver staining. Statistical analysis was performed by means of c2 log ratio. Results: Significant differences were observed when comparing the allele frequency distribution of D6S89 in patients with NSCLP and controls and in patients with NSCLP-Mx and controls. No significant differences were observed for patients with NSCLP-Sx. D6S109 and D6S105 showed no significant differences in any of the comparisons. Conclusions: Our results support the hypothesis that a NSCLP locus maps on 6p23 very close to D6S89. Results for D6S109 and D6S105 do not show a clear association. Differences observed between NSCLP-MX and Sx families seem to represent different etiologic entities. The results of the present study, plus those already published for candidate loci, TGFA and MSX1, support the hypothesis that several interacting major genes participate in the etiology of NSCLP
Subject(s)
Humans , Cleft Lip/genetics , Cleft Palate/genetics , Microsatellite Repeats , Phenotype , Chromosomes, Human, Pair 6/genetics , Case-Control Studies , Chromosome AberrationsABSTRACT
Background: Recent studies in mice have demonstrated that the Msx-1 homebox gene is implicated in cleft palate. Thus, it has been suggested that its human homologue, MSX1 (HOX-7), located in chromosome 4 could be involved in the etiology of non syndromic cleft lip palate. Aim: To study the linkage between non syndromic cleft palate and variations of MSX1 gene. Patients and methods: Seventy three patients with non syndromic cleft lip palate (34 simplex and 37 multiplex), 127 unaffected relatives of the cases (61 relatives of simplex cases and 66 relatives of multiplex cases) and 77 controls were studied. DNA was extracted from leukocytes and the intragenic microsatellite sequence was amplified by PCR. Results: A polymorphism of four alleles was observed, 1 (175 bp), 2 (173 bp), 3 (171 bp) and 4 (169 bp). Alleles 2 and 4 showed a joint variation in males with multiplex cleft lip palate and in their respective unaffected male relatives, that was significant when compared with male controls. Instead, the joint variation of alleles 1 and 4 of unaffected female relatives had significant differences with female controls. Females with multiplex cleft lip palate differed from female controls only in allele 1. Conclusions: These results support the hypothesis of a genetic heterogeneity in the etiology of non syndromic cleft lip palate
Subject(s)
Humans , Male , Female , Cleft Lip/genetics , Cleft Palate/genetics , Case-Control Studies , Alleles , Gene Frequency/genetics , Sex Characteristics , Genetic HeterogeneityABSTRACT
El síndrome del cromosoma X-frágil es la causa más frecuente de retardo mental hereditario en el varón y se asocia a un marcador citogenético ubicado en la banda Xq 27.3 (FRAXA) del cromosoma X. Durante muchos años el diagnostico estuvo basado en la identificación citogenética del marcador; sin embargo, este método no ha resultado confiable para el diagnóstico prenatal y la detección de portadores masculinos o femeninos clínicamente normales. El descubrimiento de las bases moleculares de este síndrome ha permitido desarrollar sondas que posibilitan la identificación confiable de los afectados y los portadores por análisis directo del ADN. Se describen los resultados de un estudio clínico, citogenético y molecular en la familia de una probando X frágil. En el afectado un varón de 2 años 4 meses con retraso mental y dismorfias se comprobó un sitio X frágil, pero su madre y una tía no tenían signos clínicos y sitio frágil. El análisis molecular mostró, en el paciente, una banda de 6,5 Kb, que indicaba la presencia de la mutación causal, mientras la madre exhibía dos bandas, una de 5,2 y otra de 6,0 Kb, que la identifican como heterocigota. En contraste, la tía presentó una sola banda de 5,2 Kb característica de los individuos normales