Genotype - phenotype correlation in an adolescent girl with pathogenic PPARy genetic variation that caused severe hypertriglyceridemia and early onset type 2 diabetes

Severe hypertriglyceridemia (HTG) (>885 mg/dL) can be caused by familial partial lipodystrophy type 3 (FPLD3), an autosomal dominant disorder caused by loss of function of the peroxisome proliferator-activated receptor gamma (PPARG), characterized by abnormal distribution of fat and metabolic derangements. This case reports a 16-year-old female (body mass index, 23.5 kg/m2) hospitalized twice for pancreatitis (triglycerides [TG] level >2,200 mg/dL). Her treatment management included bowel rest, insulin infusion, and plasmapheresis. A low-fat diet with 10 g of fat daily and 160 mg of fenofibrate daily decreased fasting TG to 411 mg/dL (range, 0–149 mg/dL). The patient had a normal leptin level. Panel testing of genes that impact TG metabolism revealed a known pathogenic variant in the PPARG gene (c.452A>G p.Tyr151Cys). A second variant detected in this gene, c.1003G>C (p.Val335Leu), is considered benign. Her glycosylated hemoglobin of 6.6% and 2-hour oral glucose tolerance test confirmed type 2 diabetes mellitus (T2DM). This study reports the earliest detection of T2DM in an adolescent with a pathogenic variant of PPARG. PPARG-related FPLD3 should be considered in lean children that present with severe HTG and insulin resistance, and subsequent treatment with proliferator-activated receptor gamma agonists, specifically thiazolidinediones, should be considered.

Update on the current modalities used to screen high risk youth for prediabetes and/or type 2 diabetes mellitus

The modalities currently employed to screen for type 2 diabetes mellitus (T2DM)/prediabetes are HbA1(c), fasting plasma glucose (FPG), and 2-hour plasma glucose (PG) during an oral glucose tolerance test (OGTT). The purpose of this review is to highlight the positive qualities and pitfalls of these diagnostic modalities and reflect on the most reasonable and effective approach to screen high risk youth. Given its inherent preanalytical advantages, glycated hemoglobin (HbA1(c)) continues to be the preferred diagnostic modality used by pediatricians to screen high risk youth. However, when the three aforementioned tests are performed in youths of different races/ethnicities, discrepant results for T2DM/prediabetes are observed. The prevalence rates for T2DM vary from 0.53% in Chinese youth (including youth of all body mass indexes) to 18.3% in high-risk, overweight, obese Korean youth. Moreover, the FPG is abnormal (>100 less than <126 mg/dL) in 15% of Korean youth versus 8.7% of Chinese youth. The prevalence rates for prediabetes are 1.49% in Chinese youth versus 21% in Emirati youth (HbA1(c), 5.7%–6.4%). The coefficient of agreement, k, between these screening tests for T2DM are fair, 0.45–0.5 across all youth. However, using HbA1(c) as a comparator, the agreement is weak with FPG (k=0.18 in German youth versus k=0.396 in Korean youth). The American Diabetes Association (ADA) Standards of Medical Care Guidelines define “high risk youth” who need to be tested for T2DM and/or prediabetes. OGTT and HbA1(c) do not always detect T2DM in similar individuals. HbA1(c) may not be an ideal test for screening Hispanic and African American youth. FPG and OGTT are suitable screening tests for youth of ethnic minorities and those with cystic fibrosis or hemoglobinopathies. Performing all three tests either together or sequentially may be the only way to encompass all youth who have aberrations in different aspects of glucose homeostasis.

Interpretation of androgen and anti-Mullerian hormone profiles in a Hispanic cohort of 5- to 8-year-old girls with premature adrenarche

PURPOSE: Premature adrenarche (PA) often leads to polycystic ovary syndrome (PCOS). Higher anti-mullerian hormone (AMH) levels are reported in PCOS. We studied the androgen profile and AMH profiles in Hispanic girls with PA (aged 5–8 years) and age and body mass index (BMI) matched controls. METHODS: Retrospective review of electronic medical records of girls who met the inclusion criteria for premature adrenarche were done. RESULTS: PA girls (n=76) were matched to control girls (n=12) for age (mean±standard deviation) (6.7±1 years vs. 6.2±1.3 years) and BMI (20±10 kg/m2 vs. 17.8±2.7 kg/m2). Dehydroepiandrostenedione sulfate (63.3±51.3 μg/dL vs. 29.8±17.3 μg/dL, P < 0.001) and testosterone levels (11.4±4.8 ng/dL vs. 8.2±2.9 ng/dL, P=0.001) were significantly higher in the PA group than controls. AMH values ( < 14 years: reference range, 0.49–3.15 ng/mL) were 3.2±2.2 ng/mL vs. 4.6± 3.2 ng/mL respectively in the PA and control groups and were not different (P=0.4). AMH did not show a correlation with bone age (P=0.1), and testosterone (P=0.9) in the PA group. 17-hydroxyprogesterone levels (17-OHP ng/dL) were 39.5±30.5 ng/dL vs. 36.8±19.8 ng/dL in PA versus control girls. The concentration of 17-OHP was not statistically different between the control and PA groups. CONCLUSIONS: Higher AMH was not observed in PA girls and no correlation with BA and androgen levels was observed.