Sequencing of Chromosomal Locus 6q25.1 Revealed Two Significant SNPs rs2046210 and rs2046211 Associated with Breast Cancer: A Case-Control Study in Egyptian Women.

BACKGROUND: Breast cancer (BC) is one of the major health problems affecting females in Egypt. Certain chromosomal loci abnormalities were proved to be associated with BC in different populations. One of them is chromosomal locus 6q25.1, that affects estrogen receptor gene (ESR) which controls ER receptor expression. Therefore, the aim of this study was to investigate locus 6q25.1 among group of Egyptian female BC patients and compare the results to healthy matched age controls. METHODS: Formalin fixed paraffin embedded (FFPE) samples of sixty newly diagnosed BC patients were sequenced for locus 6q25.1 using genetic analyzer with capillary electrophoresis (3500 GA). The identified single nucleotide polymorphisms (SNPs) were compared to blood samples of forty controls. Realtime PCR using TaqMan probes was used for validation. RESULTS: Two SNPs rs2046210 and rs2046211 were significantly associated with BC. Frequency of rs2046210-A minor allele was 30% in controls, while the frequency of rs2046211-G minor allele was 15%. Rs2046210-A allele was associated with increased risk of BC (P=0.0001), while rs2046211-G allele was associated with reduced risk of BC (P=0.021). Combined analysis of both SNPs showed that haplotype A/C was associated with increased risk of BC (P = 0.042). No significant correlation was found between rs2046210-A allele and ER status, while positive association was observed between rs204621-C allele and ER status (p= 0.005). CONCLUSION: Our data confirmed the important association between locus 6q25.1 and risk of BC in other populations. The frequencies of minor alleles of both significant SNPs will pave the way for a wider large-scale genome study and to be investigated with other BC risk factors.

Circulating adrenocorticotropic hormone (ACTH) and cortisol concentrations in normal, appropriate-for-gestational-age newborns versus those with sepsis and respiratory distress: Cortisol response to low-dose and standard-dose ACTH tests.

In this crossover study, we compared the peak responses of cortisol to low-dose (1 microg/1.73 m(2)) and standard-dose (250 microg/1.73 m(2)) adrenocorticotropic hormone (ACTH) stimulation tests in 90 full-term newborns (37 to 42 weeks gestational age, birthweight > 2,500 g, aged 4 to 7 days): 30 with sepsis syndrome, 30 with respiratory distress (RD) and 30 normal infants. Basal cortisol and ACTH were measured in a fasting venous sample. Serum cortisol concentrations were measured 30 minutes after low-dose ACTH and 60 minutes after standard-dose ACTH by radioimmunoassay (RIA). The mean basal circulating cortisol concentration and peak cortisol responses to low-dose and standard-dose ACTH tests were higher in stressed infants with sepsis and RD compared to normal. Basal but not ACTH-stimulated cortisol concentrations were significantly higher in newborns with sepsis versus those with RD. Circulating cortisol concentrations after the low-dose ACTH test were correlated significantly with those obtained after the standard-dose ACTH test (r = 0.814, P <.001). Clinical subgrouping of septic newborns showed that those with leukopenia (5/10 died) and with meningitis (6/12 died) had significantly lower basal and peak cortisol responses to the low-dose ACTH test (but not the standard-dose ACTH test) versus those with leukocytosis (3/20 died) and without meningitis (2/18 died), respectively. In addition, septic newborns who died had significantly lower circulating cortisol concentrations and lower cortisol responses to the low-dose ACTH test (but not the standard-dose test) versus those who survived the stress. On an individual basis, only 2 septic newborns (both died) had low basal cortisol levels (<5 microg/dL) and cortisol responses less than 15 microg/dL after the low-dose ACTH test. Four more septic newborns had basal cortisol above 5 microg/dl but cortisol responses below 20 microg/dL after the low-dose ACTH test. These 4 newborns (4/30) with inadequate adrenocortical response to low-dose ACTH during sepsis had high mortality (3/4 died) and represented a subgroup of septic newborns that should be diagnosed, using a low-dose ACTH test, and treated early. These data suggest that the low-dose ACTH test may be more disciminatory than the standard-dose test among babies under stress. Increasing the cut-point level of basal cortisol in stressed infants to the lowest level of cortisol response to low-dose ACTH in normal newborns, followed by the use of a low-dose ACTH test, appears to select some newborns who need and may improve on corticosteroid therapy. Further studies are required to investigate whether supplementation with stress doses of hydrocortisone may improve the outcome in these patients.

Serum leptin concentrations in children with type 1 diabetes mellitus: relationship to body mass index, insulin dose, and glycemic control.

Although obesity is a frequent feature of type 2 diabetes mellitus (DM), many patients with type 1 DM are prone to high body mass index (BMI). We measured serum leptin concentrations in a cohort of children (n = 55) with type 1 diabetes mellitus (DM), as well as their anthropometric parameters including BMI, skin fold thickness at multiple sites, and midarm circumference. Glycemic control was assessed by blood glucose (BG) monitoring before meals, and measurement of glycated hemoglobin (HbA1c) and insulin dose/kg/d was recorded. Dietary evaluation and assessment of caloric intake (kg/d) was performed by an expert dietitian. In the newly diagnosed children (n = 10) before initiation of insulin therapy, circulating leptin concentration was significantly lower (1.1 +/- 0.8 ng/dL) versus 5 days after insulin therapy (1.45 +/- 0.7 ng/dL). The decreased leptin level appears to be related to insulinopenia in these patients. In 45 children with type 1 DM on conventional therapy (2 doses of insulin mixture (NPH and regular) subcutaneous (SC) before breakfast and dinner for more than 2 years), serum leptin concentration was significantly higher (2.15 +/- 1 ng/dL) compared with age-matched normal children (1.3 +/- 1 ng/dL). Diabetic children were further divided into 2 groups according to their HbA1c level: group 1 with HbA1C less than 7.5% (less than 2 SD above the mean for normal population) (n = 29) and group 2 with HbA1c greater than 7.5%. (greater than 2 SD above the mean for normal population) (n = 16). Patients with a higher HbA1c level (group 2) had a higher leptin concentration (2.3 +/- 0.8 ng/dL), higher BMI (17.8 +/- 1.7), and were receiving higher insulin dose/kg (0.92 +/- 0.2 U/kg/d) compared with group 1 (lower HbA1c) (1.78 +/- 0.8 ng/dL, 16.7 +/- 1.5, and 0.59 +/- 0.2 U/kg/d, respectively). Group 2 patients had a higher incidence of late morning hypoglycemia (9/29) versus group 1 patients (2/16). Analysis of dietary intake showed that patients with a higher HbA1c (group 2) consumed more calories (73.5 +/- 10.5 kcal/kg/d) versus patients with lower HbA1c (64.2 +/- 8.7 kcal/kg/d). These findings pointed to the unphysiologic nature of injecting a mixture of insulin twice daily. To cover the relatively big lunch meal (40% to 50% of the total caloric intake in the Arab countries) and prevent afternoon hyperglycemia, there is a great tendency to increase NPH dose before breakfast. This, in turn, induces late-morning hypoglycemia and increases appetite and food intake at that time. Multiple regression analysis showed that circulating leptin concentrations (the dependent variable) were best correlated with the mean skinfold thickness (SFT), BMI, and caloric intake/kg/d (together they explained 65% of the variability in leptin concentrations). It appears that oversubstitution by insulin and increased food intake stimulate fat synthesis and subsequently BMI. Increased appetite and BMI contribute to increased leptin secretion and explains the higher leptin levels in undercontrolled diabetic children (higher circulating HbA1c concentrations) who were oversubstituted by insulin.