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Vitamin D Status and VDR Genotype in NF1 Patients: A Case-Control Study from Southern Brazil.

Souza Mario Bueno L, Rosset C, Aguiar E, Pereira Fde S, Izetti Ribeiro P, Scalco R, Matzenbacher Bittar C, Brinckmann Oliveira Netto C, Gischkow Rucatti G, Chies JA, Camey SA, Ashton-Prolla P - Int J Endocrinol (2015)

Bottom Line: Vitamin D levels were compared between a group of 45 NF1 patients from Southern Brazil and 45 healthy controls matched by sex, skin type, and age.We also did not observe an association between FokI and BsmI VDR gene polymorphisms and vitamin D levels in NF1 patients, suggesting that their deficient or insufficient biochemical phenotypes are not associated with these genetic variants.These polymorphisms are in partial linkage disequilibrium and the haplotype frequencies also did not differ in a significant way between the two groups (p = 0.613).

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Medicina Genômica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil ; Programa de Pós Graduação em Medicina: Ciências Médicas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil ; Universidade Vila Velha, Vila Velha, ES, Brazil ; Hospital Metropolitano, Serra, ES, Brazil.

ABSTRACT
Neurofibromatosis type 1 (NF1) patients are more likely to have vitamin D deficiency when compared to the general population. This study aimed to determine the levels of 25-OH-vitamin D [25(OH)D] in individuals with NF1 and disease-unaffected controls and analyze FokI and BsmI VDR gene polymorphisms in a case and in a control group. Vitamin D levels were compared between a group of 45 NF1 patients from Southern Brazil and 45 healthy controls matched by sex, skin type, and age. Genotypic and allelic frequencies of VDR gene polymorphisms were obtained from the same NF1 patients and 150 healthy controls. 25(OH)D deficiency or insufficiency was not more frequent in NF1 patients than in controls (p = 0.074). We also did not observe an association between FokI and BsmI VDR gene polymorphisms and vitamin D levels in NF1 patients, suggesting that their deficient or insufficient biochemical phenotypes are not associated with these genetic variants. The differences between the groups in genotypic and allelic frequencies for FokI and BsmI VDR gene polymorphisms were small and did not reach statistical significance. These polymorphisms are in partial linkage disequilibrium and the haplotype frequencies also did not differ in a significant way between the two groups (p = 0.613).

No MeSH data available.


Related in: MedlinePlus

Histograms showing the distribution of plasma 25(OH)D levels (ng/mL) in NF1 patients (a) and controls (b).
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fig1: Histograms showing the distribution of plasma 25(OH)D levels (ng/mL) in NF1 patients (a) and controls (b).

Mentions: Clinical and demographic features of the patients and controls used to determine vitamin D status are summarized in Tables 1 and 2. There was no significant difference between groups in age at assessment, sex, skin type (according to the Fitzpatrick classification, avoidance of sun exposure), habit of smoking, or use of alcohol. As expected, patients with NF1 had an increased frequency of short stature and had been more often diagnosed with cancer when compared to controls. The mean body mass index (BMI) for NF1 patients was 24,61 and 24,20 for controls, showing no difference between groups for this measure. The mean and median 25(OH)D levels in NF1 patients were 25.25 ng/mL and 25.10 ng/mL (±8.46), respectively, and 22.79 ng/mL and 21.90 ng/mL (±6.28) in controls, respectively. There was no statistically significant difference in mean 25(OH)D levels between the NF1 and control groups (p = 0.074). In the NF1 group, 29 (64.4%) of the 45 individuals studied had levels of 25(OH)D below 30 ng/mL: vitamin D deficiency was observed in 11 (24.4%) and vitamin D insufficiency in 18 (40.0%) subjects. The minimum 25(OH)D level detected in this group was 5.27 ng/mL and maximum level was 41.3 ng/mL. In the control group, 39 (86.6%) of the 45 individuals studied had levels of 25(OH)D below 30 ng/mL: vitamin D deficiency was observed in 17 (37.7%) and vitamin D insufficiency in 22 (48.8%) subjects. The minimum 25(OH)D level detected in this group was 14.1 ng/mL and maximum level was 44.3 ng/mL. When we categorized 25(OH)D using a cutoff of 30 ng/mL, NF1 patients had more frequently normal 25(OH)D levels than controls. Although this difference did not reach statistical significance, distinct distribution can be further observed in the 25(OH)D levels (ng/mL) histograms depicted in Figure 1. We did not observe a more severe phenotype in NF1 patients with lower 25(OH)D levels (data not shown).


Vitamin D Status and VDR Genotype in NF1 Patients: A Case-Control Study from Southern Brazil.

Souza Mario Bueno L, Rosset C, Aguiar E, Pereira Fde S, Izetti Ribeiro P, Scalco R, Matzenbacher Bittar C, Brinckmann Oliveira Netto C, Gischkow Rucatti G, Chies JA, Camey SA, Ashton-Prolla P - Int J Endocrinol (2015)

Histograms showing the distribution of plasma 25(OH)D levels (ng/mL) in NF1 patients (a) and controls (b).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4487339&req=5

fig1: Histograms showing the distribution of plasma 25(OH)D levels (ng/mL) in NF1 patients (a) and controls (b).
Mentions: Clinical and demographic features of the patients and controls used to determine vitamin D status are summarized in Tables 1 and 2. There was no significant difference between groups in age at assessment, sex, skin type (according to the Fitzpatrick classification, avoidance of sun exposure), habit of smoking, or use of alcohol. As expected, patients with NF1 had an increased frequency of short stature and had been more often diagnosed with cancer when compared to controls. The mean body mass index (BMI) for NF1 patients was 24,61 and 24,20 for controls, showing no difference between groups for this measure. The mean and median 25(OH)D levels in NF1 patients were 25.25 ng/mL and 25.10 ng/mL (±8.46), respectively, and 22.79 ng/mL and 21.90 ng/mL (±6.28) in controls, respectively. There was no statistically significant difference in mean 25(OH)D levels between the NF1 and control groups (p = 0.074). In the NF1 group, 29 (64.4%) of the 45 individuals studied had levels of 25(OH)D below 30 ng/mL: vitamin D deficiency was observed in 11 (24.4%) and vitamin D insufficiency in 18 (40.0%) subjects. The minimum 25(OH)D level detected in this group was 5.27 ng/mL and maximum level was 41.3 ng/mL. In the control group, 39 (86.6%) of the 45 individuals studied had levels of 25(OH)D below 30 ng/mL: vitamin D deficiency was observed in 17 (37.7%) and vitamin D insufficiency in 22 (48.8%) subjects. The minimum 25(OH)D level detected in this group was 14.1 ng/mL and maximum level was 44.3 ng/mL. When we categorized 25(OH)D using a cutoff of 30 ng/mL, NF1 patients had more frequently normal 25(OH)D levels than controls. Although this difference did not reach statistical significance, distinct distribution can be further observed in the 25(OH)D levels (ng/mL) histograms depicted in Figure 1. We did not observe a more severe phenotype in NF1 patients with lower 25(OH)D levels (data not shown).

Bottom Line: Vitamin D levels were compared between a group of 45 NF1 patients from Southern Brazil and 45 healthy controls matched by sex, skin type, and age.We also did not observe an association between FokI and BsmI VDR gene polymorphisms and vitamin D levels in NF1 patients, suggesting that their deficient or insufficient biochemical phenotypes are not associated with these genetic variants.These polymorphisms are in partial linkage disequilibrium and the haplotype frequencies also did not differ in a significant way between the two groups (p = 0.613).

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Medicina Genômica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil ; Programa de Pós Graduação em Medicina: Ciências Médicas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil ; Universidade Vila Velha, Vila Velha, ES, Brazil ; Hospital Metropolitano, Serra, ES, Brazil.

ABSTRACT
Neurofibromatosis type 1 (NF1) patients are more likely to have vitamin D deficiency when compared to the general population. This study aimed to determine the levels of 25-OH-vitamin D [25(OH)D] in individuals with NF1 and disease-unaffected controls and analyze FokI and BsmI VDR gene polymorphisms in a case and in a control group. Vitamin D levels were compared between a group of 45 NF1 patients from Southern Brazil and 45 healthy controls matched by sex, skin type, and age. Genotypic and allelic frequencies of VDR gene polymorphisms were obtained from the same NF1 patients and 150 healthy controls. 25(OH)D deficiency or insufficiency was not more frequent in NF1 patients than in controls (p = 0.074). We also did not observe an association between FokI and BsmI VDR gene polymorphisms and vitamin D levels in NF1 patients, suggesting that their deficient or insufficient biochemical phenotypes are not associated with these genetic variants. The differences between the groups in genotypic and allelic frequencies for FokI and BsmI VDR gene polymorphisms were small and did not reach statistical significance. These polymorphisms are in partial linkage disequilibrium and the haplotype frequencies also did not differ in a significant way between the two groups (p = 0.613).

No MeSH data available.


Related in: MedlinePlus