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  • Author: Henri J L M Timmers x
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Hanneke J B H Beijers, Nike M L Stikkelbroeck, Arjen R Mensenkamp, Rolph Pfundt, Rob B van der Luijt, Henri J L M Timmers, Ad R M M Hermus and Marlies J E Kempers

Context

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disease caused by mutations in the tumor suppressor gene MEN1 and can be diagnosed based on clinical, familial and/or genetic criteria. We present a family in which we found both germline and somatic mosaicism for MEN1.

Family description

In our proband, we diagnosed MEN1. The mutation was not detected in her parents (DNA extracted from leucocytes). When her brother was found to harbor the same MEN1 mutation as our proband and, around the same time, their father was diagnosed with a neuroendocrine carcinoma, this tumor was investigated for the MEN1 mutation as well. In the histologic biopsy of this tumor, the same MEN1 mutation was detected as previously found in his children. Re-analysis of his blood using multiplex ligation-dependent probe amplification (MLPA) showed a minimal, but consistently decreased signal for the MEN1-specific MLPA probes. The deletion was confirmed in his son by high-resolution array analysis. Based on the array data, we concluded that the deletion was limited to the MEN1 gene and that the father had both germline and somatic mosaicism for MEN1.

Conclusions

To our knowledge, this is the first reported family with combined germline and somatic mosaicism for MEN1. This study illustrates that germline mosaicism is important to consider in apparently sporadic de novo MEN1 mutations, because of its particular importance for genetic counseling, specifically when evaluating the risk for family members and when considering the possibility of somatic mosaicism in the parent with germline mosaicism.

Open access

Dipti Rao, Mirko Peitzsch, Aleksander Prejbisz, Katarzyna Hanus, Martin Fassnacht, Felix Beuschlein, Christina Brugger, Stephanie Fliedner, Katharina Langton, Christina Pamporaki, Volker Gudziol, Anthony Stell, Andrzej Januszewicz, Henri J L M Timmers, Jacques W M Lenders and Graeme Eisenhofer

Context

Measurements of plasma methoxytyramine, the O-methylated dopamine metabolite, are useful for detecting rare dopamine-producing pheochromocytomas and paragangliomas (PPGLs) and head and neck paragangliomas (HNPGLs), but utility for screening beyond that achieved using standard measurements of normetanephrine and metanephrine is unclear.

Objective

Evaluation of the additional utility of methoxytyramine compared to plasma normetanephrine and metanephrine for diagnosis of PPGLs and HNPGLs.

Design

Comparative prospective study.

Methods

Comparison of mass spectrometric-based measurements of plasma methoxytyramine, normetanephrine and metanephrine in 1963 patients tested for PPGLs at six tertiary medical centers according to reference intervals verified in 423 normotensive and hypertensive volunteers.

Results

Of the screened patients, 213 had PPGLs and 38 HNPGLs. Using an upper cut-off of 0.10 nmol/L for methoxytyramine, 0.45 nmol/L for metanephrine and age-specific upper cut-offs for normetanephrine, diagnostic sensitivity with the addition of methoxytyramine increased from 97.2% to 98.6% for patients with PPGLs and from 22.1% to 50.0% for patients with HNPGLs, with a small decrease in specificity from 95.9% to 95.1%. Addition of methoxytyramine did not significantly alter areas under receiver operating characteristic curves for patients with PPGLs (0.984 vs 0.991), but did increase (P < 0.05) areas for patients with HNPGLs (0.627 vs 0.801). Addition of methoxytyramine also increased the proportion of patients with PPGLs who showed highly positive predictive elevations of multiple metabolites (70.9% vs 49.3%).

Conclusions

While the benefit of additional measurements of plasma methoxytyramine for the detection of PPGLs is modest, the measurements do assist with positive confirmation of disease and are useful for the detection of HNPGLs.

Free access

Kim Freriks, Theo C J Sas, Maaike A F Traas, Romana T Netea-Maier, Martin den Heijer, Ad R M M Hermus, Jan M Wit, Janiëlle A E M van Alfen-van der Velden, Barto J Otten, Sabine M P F de Muinck Keizer-Schrama, Martin Gotthardt, Philippe H Dejonckere, Gladys R J Zandwijken, Leonie A Menke and Henri J L M Timmers

Objective

Short stature is a prominent feature of Turner syndrome (TS), which is partially overcome by GH treatment. We have previously reported the results of a trial on the effect of oxandrolone (Ox) in girls with TS. Ox in a dose of 0.03 mg/kg per day (Ox 0.03) significantly increased adult height gain, whereas Ox mg/kg per day (0.06) did not, at the cost of deceleration of breast development and mild virilization. The aim of this follow-up study in adult participants of the pediatric trial was to investigate the long-term effects of previous Ox treatment.

Design and methods

During the previous randomized controlled trial, 133 girls were treated with GH combined with placebo (Pl), Ox 0.03, or Ox 0.06 from 8 years of age and estrogen from 12 years. Sixty-eight women (Pl, n=23; Ox 0.03, n=27; and Ox 0.06, n=18) participated in the double-blind follow-up study (mean age, 24.0 years; mean time since stopping GH, 8.7 years; and mean time of Ox/Pl use, 4.9 years). We assessed height, body proportions, breast size, virilization, and body composition.

Results

Height gain (final minus predicted adult height) was maintained at follow-up (Ox 0.03 10.2±4.9 cm, Ox 0.06 9.7±4.4 cm vs Pl 8.0±4.6 cm). Breast size, Tanner breast stage, and body composition were not different between groups. Ox-treated women reported more subjective virilization and had a lower voice frequency.

Conclusion

Ox 0.03 mg/kg per day has a beneficial effect on adult height gain in TS patients. Despite previously reported deceleration of breast development during Ox 0.03 treatment, adult breast size is not affected. Mild virilization persists in only a small minority of patients. The long-term evaluation indicates that Ox 0.03 treatment is effective and safe.

Restricted access

Edward Buitenwerf, Tijmen Korteweg, Anneke Visser, Charlotte M S C Haag, Richard A Feelders, Henri J L M Timmers, Letizia Canu, Harm R Haak, Peter H L T Bisschop, Elisabeth M W Eekhoff, Eleonora P M Corssmit, Nanda C Krak, Elise Rasenberg, Janneke van den Bergh, Jaap Stoker, Marcel J W Greuter, Robin P F Dullaart, Thera P Links and Michiel N Kerstens

Background

A substantial proportion of all pheochromocytomas is currently detected during the evaluation of an adrenal incidentaloma. Recently, it has been suggested that biochemical testing to rule out pheochromocytoma is unnecessary in case of an adrenal incidentaloma with an unenhanced attenuation value ≤10 Hounsfield Units (HU) at computed tomography (CT).

Objectives

We aimed to determine the sensitivity of the 10 HU threshold value to exclude a pheochromocytoma.

Methods

Retrospective multicenter study with systematic reassessment of preoperative unenhanced CT scans performed in patients in whom a histopathologically proven pheochromocytoma had been diagnosed. Unenhanced attenuation values were determined independently by two experienced radiologists. Sensitivity of the 10 HU threshold was calculated, and interobserver consistency was assessed using the intraclass correlation coefficient (ICC).

Results

214 patients were identified harboring a total number of 222 pheochromocytomas. Maximum tumor diameter was 51 (39–74) mm. The mean attenuation value within the region of interest was 36 ± 10 HU. Only one pheochromocytoma demonstrated an attenuation value ≤10 HU, resulting in a sensitivity of 99.6% (95% CI: 97.5–99.9). ICC was 0.81 (95% CI: 0.75–0.86) with a standard error of measurement of 7.3 HU between observers.

Conclusion

The likelihood of a pheochromocytoma with an unenhanced attenuation value ≤10 HU on CT is very low. The interobserver consistency in attenuation measurement is excellent. Our study supports the recommendation that in patients with an adrenal incidentaloma biochemical testing for ruling out pheochromocytoma is only indicated in adrenal tumors with an unenhanced attenuation value >10 HU.

Free access

Nicolasine D Niemeijer, Johannes A Rijken, Karin Eijkelenkamp, Anouk N A van der Horst-Schrivers, Michiel N Kerstens, Carli M J Tops, Anouk van Berkel, Henri J L M Timmers, Henricus P M Kunst, C René Leemans, Peter H Bisschop, Koen M A Dreijerink, Marieke F van Dooren, Jean-Pierre Bayley, Alberto M Pereira, Jeroen C Jansen, Frederik J Hes, Erik F Hensen and Eleonora P M Corssmit

Objective

Succinate dehydrogenase B subunit (SDHB) gene germline mutations predispose to pheochromocytomas, sympathetic paragangliomas, head and neck paragangliomas and non-paraganglionic tumors (e.g. renal cell carcinoma, gastrointestinal stromal tumor and pituitary neoplasia). The aim of this study was to determine phenotypical characteristics of a large Dutch cohort of SDHB germline mutation carriers and assess differences in clinical phenotypes related to specific SDHB mutations.

Design

Retrospective descriptive study.

Methods

Retrospective descriptive study in seven academic centers.

Results

We included 194 SDHB mutation carriers consisting 65 (33.5%) index patients and 129 (66.5%) relatives. Mean age was 44.8 ± 16.0 years. Median duration of follow-up was 2.6 years (range: 0–36). Sixty persons (30.9%) carried the exon 3 deletion and 46 (23.7%) the c.423 + 1G > A mutation. Fifty-four mutation carriers (27.8%) had one or multiple head and neck paragangliomas, 4 (2.1%) had a pheochromocytoma and 26 (13.4%) had one or more sympathetic paragangliomas. Fifteen patients (7.7%) developed metastatic paraganglioma and 17 (8.8%) developed non-paraganglionic tumors. At study close, there were 111 (57.2%) unaffected mutation carriers. Statistical analyses showed no significant differences in the number and location of head and neck paragangliomas, sympathetic paragangliomas or pheochromocytomas, nor in the occurrence of metastatic disease or other tumors between carriers of the two founder SDHB mutations (exon 3 deletion vs c.423+ 1G > A).

Conclusions

In this nationwide study of disease-affected and unaffected SDHB mutation carriers, we observed a lower rate of metastatic disease and a relatively high number of head and neck paragangliomas compared with previously reported referral-based cohorts.