Spectrum of phenotype and genotype of congenital isolated hypogonadotropic hypogonadism in Asian Indians.

BACKGROUND: Congenital isolated hypogonadotropic hypogonadism (IHH) is caused due to defect in GnRH neuronal development, migration and action. Although genetic aetiology of IHH is increasingly being studied, Asian Indian data on phenotypic spectrum and genetic basis are scarce. OBJECTIVE: To investigate the phenotypic and genotypic spectrum of IHH in Asian Indian subjects. DESIGN, SETTING AND SUBJECTS: A cohort of 135 IHH probands were characterized phenotypically for reproductive and nonreproductive features and screened for rare sequence variations (RSVs) in five genes KAL1, FGFR1, FGF8, GNRHR and KISS1R. RESULT: Of 135 probands [56 normosmic IHH (nIHH) and 79 Kallmann syndrome (KS)], 20 were familial cases. KS group had more male dominance (M:F ratio of 8:1) as compared to nIHH group (M:F ratio of 1·5:1). Complete absence of puberty was more prevalent in KS probands (81% in KS vs 46% in nIHH). The prevalence of MRI abnormalities was more in anosmic group (92·8%) as compared to hyposmic (37·5%) and normosmic groups (15·4%). No particular nonreproductive phenotypic predominance was seen in any group. Genotyping revealed rare sequence variation (RSV) detection rate of 15·5% in five genes studied: (KAL1 - 4·4%, FGFR1 - 4·4%, GNRHR - 6·7%, oligogenicity - 1·5%). Prevalence of RSV was more common in familial cases (35%) as compared to sporadic (12·2%). GNRHR RSV p.C279Y (not reported in patients of ethnicities other than south Asians) was recurring in four unrelated patients. CONCLUSION: In our cohort, 60% were KS with majority of males and a severe reproductive phenotype as against nIHH. Contribution of the genetic burden for the five genes studied was 15·5%. RSV p.C279Y in GNRHR may have a founder effect originating from south Asia. This study provides a model for molecular and phenotypic representation of Asian Indian subjects with IHH.

Genotype phenotype correlation in Asian Indian von Hippel-Lindau (VHL) syndrome patients with pheochromocytoma/paraganglioma.

The data in genotype-phenotype correlation in Indian von Hippel-Lindau (VHL) patients is limited. We have retrospectively studied 31 genetically proven VHL patients with pheochromocytoma/paraganglioma (PCC/PGL) from families and have reviewed the World literature on PCC/PGL in patients with large VHL deletions. Three patients had large deletions and 28 patients had other mutations [missense mutations in 25, 3 bp deletion in 2 and single bp duplication in one]. Unilateral PCC were significantly more common in patients with large VHL deletions whereas multiple PCC (bilateral PCC or PCC + sympathetic PGL) were significantly more common in those with other mutations. World literature review confirmed the rarity of PCC/PGL in patients with large deletions and we report the first definitive case of PCC associated with complete VHL deletion. Pancreatic neuroendocrine tumours were more common, often metastatic and the most common cause of death in our cohort. Our study had eight parent off-spring pairs from five families. The off-springs were significantly younger at presentation and had significantly higher number of PCC/PGL. In conclusion, PCC/PGL are rare in patients with large VHL deletions and if occur are most likely to be solitary. Patients with bilateral PCC or multifocal PCC/PGL are least likely to have large VHL deletions. Our study also provides additional evidence for existence of the phenomenon of anticipation in VHL syndrome.

Genotype-phenotype correlation in paediatric pheochromocytoma and paraganglioma: a single centre experience from India.

BACKGROUND: Data on genotype-phenotype correlation in children is limited. Hence, we studied the prevalence of germline mutations and genotype-phenotype correlation in children with pheochromocytoma (PCC)/paraganglioma (PGL) and compared it with adult PCC/PGL cohort. METHODS: A total of 121 consecutive, unrelated, index PCC/PGL patients underwent genetic testing for five PCC/PGL susceptibility genes (RET, VHL, SDHB, SDHD and SDHC) and were evaluated for clinical diagnosis of neurofibromatosis type1 (NF1). RESULTS: Thirty patients (12 boys, 18 girls) presented at ≤20 years of age (mean age of 15.9±3.8 years). Children were more frequently symptomatic and more frequently had bilateral PCC than adults. Fourteen (46.7%) PCC/PGL children had germline mutations (VHL 10 [33.3%], SDHB 2 [6.6%], and SDHD 2 [6.6%]). Overall germline mutations (46.7% vs. 26.4%, p=0.04) and VHL mutations (33.3% vs. 10.9%, p=0.026) were significantly more common in children than in adults. In children with VHL mutations, bilateral PCC were more frequent than in adults with VHL mutations. Within the paediatric cohort, bilateral PCC (60% vs. 5%, p=0.002), PCC+sPGL (30% vs. 0%, p=0.03) and occurrence of a second PCC/PGL (30% vs. 0%, p=0.03) were significantly more frequent among children with VHL mutations than others. CONCLUSIONS: All PCC/PGL children should be screened for germline mutations with first priority for VHL gene testing. Paediatric PCC/PGL patients with VHL mutations should be thoroughly evaluated for bilateral PCC and PCC+sPGL at initial presentation and closely followed up for occurrence of a second PCC/PGL.

Genetic status determines 18 F-FDG uptake in pheochromocytoma/paraganglioma.

INTRODUCTION: Although few studies have demonstrated utility of 18 F- fluoro-2-deoxy-d-glucose positron emission tomography/computerised tomography (18 F-FDG PET/CT) in benign pheochromocytoma/paragangliomas (PCC/PGLs), there limited data on factors predicting the FDG uptake in PCC/PGL. METHODS: The study was conducted at a tertiary health care centre. In addition to the routine investigations, all patients (n = 96) with PCC/PGL were evaluated with 18 F-FDGPET/CT and majority (n = 78) underwent 131 I-metaiodobenzyl guanidine (131 I-MIBG) scintigraphy. Forty-three patients also underwent testing for germline mutations in five PCC/PGL susceptibility genes (VHL, RET, SDHB, SDHC and SDHD) and all patients were evaluated clinically for neurofibromatosis-1. RESULTS: The study included 96 patients with PCC/PGL(82 benign and 14 malignant). FDGSUVmax was significantly higher for malignant than benign PCC/PGL(P = 0.009) and for extra-adrenal PGL than adrenal PCC (P = 0.017). In subgroup analysis, metanephrine-secreting PCC and non-secretory PCC had significantly lower FDG SUVmax than normetanephrine-secreting PCC (P = 0.017, P = 0.038 respectively), normetanephrine-secreting-sympathetic PGL (P = 0.008, P = 0.019 respectively) and non-secretory sympathetic PGL (P = 0.003, P = 0.009 respectively). Patients with mutations in cluster 1 genes (n = 14) had significantly higher FDG SUVmax than those with mutations in cluster 2 genes (n = 4) (P = 0.04). Sensitivities of 131 I-MIBG and 18 F-FDG PET/CTwere 77.78% and 100% for cluster 1 genes-related PCC/PGL whereas they were 100% and 50% for cluster 2 genes-related PCC/PGL, respectively. Multivariate regression analysis of mutation positive patients identified genetic status as the only independent predictor of FDG SUVmax. CONCLUSION: The study suggests that the underlying genetic status determines FDG uptake in PCC/PGL and not location, secretory status or malignancy.

Predictors of malignancy in patients with pheochromocytomas/paragangliomas: Asian Indian experience.

BACKGROUND AND AIMS: Malignant transformation of pheochromocytomas/paragangliomas (PCC/PGL) is a rare occurrence, and predictive factors for the same are not well understood. This study aims to identify the predictors of malignancy in patients with PCC/PGL. MATERIALS AND METHODS: We performed a retrospective analysis of 142 patients with either PCC or PGL registered at our institute between 2000 and 2015. Records were evaluated for clinical parameters like age, gender, familial/syndromic presentation, symptomatic presentation, biochemistry, size, number and location of tumours and presence of metastases and mode of its diagnosis. RESULTS: Twenty patients were found to have metastases; 13 had metastases at diagnosis and seven during follow-up. Metastases were detected by radiology (CT-neck to pelvis) in 11/20 patients (5/13 synchronous and 6/7 metachronous), 131I-metaiodobenzylguanidine in five (2/12 synchronous and 3/6 metachronous) patients and 18F-flurodeoxyglucose PET/CT in 15 (12/12 synchronous and 3/3 metachronous) patients. Malignant tumours were significantly larger than benign tumours (8.3 ± 4.1 cm, range: 3-22 cm vs 5.7 ± 2.3 cm, range: 2-14 cm, P = 0.0001) and less frequently metanephrine secreting. On linear regression analysis, tumour size and lack of metanephrine secretion were the independent predictors of malignancy. CONCLUSIONS: Patients with primary tumour size >5.7 cm and lack of metanephrine secretory status should be evaluated for possible malignancy not only at diagnosis but also in the postoperative period. As compared to CT and 131I-MIBG scan, 18F-flurodeoxyglucose PET/CT analyses are better (sensitivity: 100%) for the diagnosis of metastases in our study.

Germline mutations and genotype-phenotype correlation in Asian Indian patients with pheochromocytoma and paraganglioma.

BACKGROUND: Genetic aetiology of pheochromocytoma (PCC) and paraganglioma (PGL) is increasingly being studied; however, Asian Indian data on this aspect are scarce. OBJECTIVE: To study the prevalence of germline mutations and genotype-phenotype correlation in Asian Indian PCC/PGL patients. DESIGN: In this study, 150 index patients (M:F, 73:77) with PCC/PGL were evaluated. Phenotypic data were collected. Germline mutations in five susceptibility genes (RET, VHL, SDHB, SDHD and SDHC) were tested by sequencing and NF1 was diagnosed according to phenotype. RESULT: Of the total population, 49 (32.7%) PCC/PGL patients had germline mutations (VHL: 23 (15.3%), RET: 13 (8.7%), SDHB: 9 (6%), SDHD: 2 (1.3%) and NF1: 2 (1.3%)). Amongst the 30 patients with familial and/or syndromic presentation, all had germline mutations (VHL: 14 (46.7%), RET: 13 (43.3%), SDHB: 1 (3.3%) and NF1: 2 (6.7%)). Out of 120 patients with apparently sporadic presentation, 19 (15.8%) had a germline mutation (VHL: 9 (7.5%), SDHB: 8 (6.7%) and SDHD: 2 (1.7%)). Mutation carriers were younger (29.9 ± 14.5 years vs 36.8 ± 14.9; P = 0.01) and had a higher prevalence of bilateral PCC (26.5% vs 2.9%, P < 0.001) and multifocal tumours (12.2% vs 0.96%, P = 0.06). Based on syndromic features, metastasis, location and number of tumours, around 96% mutations in our cohort could be detected by appropriately selected single gene testing. CONCLUSION: Asian Indians with PCC/PGL differ from Western cohorts in having preponderance of VHL mutations in multifocal tumours and apparently sporadic unilateral PCC. Syndromic presentation, metastasis, location and number of PCC/PGL can be effectively used for guiding genetic prioritisation.

Pheochromocytoma and tetralogy of Fallot: a rare but potentially dangerous combination.

OBJECTIVE: To describe a case of pheochromocytoma (PHEO) with tetralogy of Fallot (TOF) and discuss the difficulties encountered during the management of this patient, with a review of the literature. METHODS: We report the clinical course, imaging, and management issues of our patient and review relevant literature. RESULTS: A 14-year-old female who was known to have TOF presented with classical paroxysmal symptoms and worsening dyspnea. She was diagnosed as having epinephrine-secreting PHEO based on biochemical, radiologic, and functional imaging. She was treated with an α-1 blocker for control of paroxysms but developed severe cyanotic spells. She required addition of a calcium-channel blocker for control of the paroxysms and underwent successful cardiac repair. CONCLUSION: Treatment of the combination of cyanotic congenital heart disease (CCHD) and PHEO requires an individualized and multidisciplinary approach with judicious use of available medications. This is the first case of uncorrected TOF and epinephrine-secreting PHEO. Our case also reiterates the need for further studies to better understand the pathophysiologic link between PHEO/paraganglioma and CCHD.

Performance of plasma fractionated free metanephrines by enzyme immunoassay in the diagnosis of pheochromocytoma and paraganglioma in children.

OBJECTIVE: To establish pediatric reference ranges for plasma fractionated free metanephrines by enzyme immunoassay (EIA) and to evaluate its performance in the diagnosis of catecholamine-secreting tumors in the pediatric population. METHODS: Normotensive children and children with suspected catecholamine-secreting tumors underwent measurement of plasma fractionated metanephrines by EIA to establish pediatric reference ranges. Children with suspected pheochromocytoma or paraganglioma also underwent magnetic resonance imaging or computed tomography from the neck to the pelvis and were followed up for a minimum of 1 year. Diagnosis of pheochromocytoma/paraganglioma was confirmed by histologic examination. Pheochromocytoma/paraganglioma was excluded in children who had a histologic diagnosis other than pheochromocytoma/paraganglioma and in those who had no imaging evidence of tumor and no progression on follow-up. RESULTS: Plasma fractionated metanephrines were measured in 78 normotensive children (age range, 1.5-17 years) and in 38 children with suspected catecholamine-secreting tumors. Of the 38 children (age range, 6-17 years) with suspected pheochromocytoma/paraganglioma, 17 had a histopathologically proven catecholamine-secreting tumor. The newly derived pediatric upper reference limit for metanephrine (128 pg/mL) was higher than in adults (90 pg/mL), whereas the pediatric upper reference limit for normetanephrine (149 pg/mL) was lower than in adults (180 pg/mL). The manufacturer's reference range for plasma fractionated metanephrines yielded a sensitivity of 100% and a specificity of 85.7%. Use of newly established pediatric reference ranges increased the specificity to 95.2% without altering the sensitivity (100%). CONCLUSIONS: Plasma fractionated metanephrines by EIA provide an accurate test with good sensitivity and specificity for the diagnosis of pheochromocytoma and paraganglioma in children. Use of pediatric reference ranges improves accuracy of the test.

Performance of plasma fractionated free metanephrines by enzyme immunoassay in the diagnosis of pheochromocytoma and paraganglioma.

OBJECTIVE: To study the performance of measuring plasma fractionated free metanephrines by enzyme immunoassay (EIA) in the diagnosis of pheochromocytoma and catecholamine-secreting paraganglioma. METHODS: Consecutive patients attending the endocrine clinic at King Edward Memorial Hospital, Mumbai, India, for suspicion of catecholamine-secreting tumors were included. Plasma fractionated free metanephrines were measured by EIA, and computed tomography of the neck, chest, abdomen, and pelvis was performed. Those with tumor identified by imaging underwent 131I m-iodobenzylguanidine scintigraphy. All patients with adrenal masses larger than 3 cm and patients with secretory tumors, irrespective of their size, underwent tumor excision. The rest were followed up for 6 to 12 months. RESULTS: One hundred patients with a clinical suspicion of pheochromocytoma or paraganglioma were included. Plasma free normetanephrine alone had a sensitivity of 94.1% (cutoff: 180 ng/mL), while plasma free metanephrine had a sensitivity of 14.7% (cutoff: 90 pg/mL). Both had 96.9% specificity. When combined (either test positive), the sensitivity was 94.1% with a specificity of 93.75%. Thirty-four patients had a histopathologically proven pheochromocytoma or paraganglioma. It was concluded that 66 patients did not harbor a pheochromocytoma or catecholamine-secreting paraganglioma. CONCLUSION: Plasma fractionated free metanephrines measured by EIA have good sensitivity and specificity in the diagnosis of pheochromocytoma and catecholamine-secreting paraganglioma.

Formulation and evaluation of trimetazidine dihydrochloride extended release tablets by melt congealing method.

Trimetazidine dihydrochloride, a cellular antiischemic agent indicated in the management and prophylaxis of angina pectoris is given as 20 mg thrice daily in the conventional dosage regimen. The purpose of the present study was to formulate and evaluate twice a day extended release tablets containing 30 mg trimetazidine dihydrochloride. The method developed to formulate these extended release tablets was melt congealing followed by wet granulation which exhibited uniform sustained release action and overcame the drawbacks of multidosing. The formulation was developed with Methocel(®) K100M and stearic acid as release retardant.