Homozygous TMEM127 mutations in 2 patients with bilateral pheochromocytomas.

Pheochromocytoma (PCC) and paraganglioma (PGL) are rare neuroendocrine tumors that are hereditary in up to 50% of patients. The gene encoding transmembrane-protein-127 (TMEM127) is one of the PCC/PGL-susceptibility genes with an autosomal dominant inheritance pattern. Here, we report 2 patients with bilateral PCC who both harbored a homozygous TMEM127-mutation. In a 31-year-old mentally retarded patient, the homozygous c.410-2A > G mutation was discovered during an update of DNA analysis. A 26-year-old mentally retarded patient was found to have a homozygous c.3G > A mutation. The parents of both patients were consanguineous. We reviewed previously reported clinical features of TMEM127 mutation carriers and compared our findings with case descriptions of homozygous mutations in other PGL/PCC-susceptibility genes. Homozygosity for an autosomal dominant inherited disorder is an extremely rare phenomenon and has, to our knowledge, not been reported before for the gene encoding TMEM127. In the present cases, the clinical picture does not seem to be very different from heterozygous TMEM127 mutation carriers, except for a relatively large tumor size and more pronounced plasma metanephrine concentration. It is unclear whether the mental retardation is causally related to homozygosity of the TMEM127 mutations. Updating genetic screening in patients in whom PCC/PGL has been diagnosed in the past should be considered as it might provide clinically relevant information.

Impact of rapid genetic counselling and testing on the decision to undergo immediate or delayed prophylactic mastectomy in newly diagnosed breast cancer patients: findings from a randomised controlled trial.

BACKGROUND: Female breast cancer patients with a BRCA1/2 mutation have an increased risk of contralateral breast cancer. We investigated the effect of rapid genetic counselling and testing (RGCT) on choice of surgery. METHODS: Newly diagnosed breast cancer patients with at least a 10% risk of a BRCA1/2 mutation were randomised to an intervention group (offer of RGCT) or a control group (usual care; ratio 2 : 1). Primary study outcomes were uptake of direct bilateral mastectomy (BLM) and delayed contralateral prophylactic mastectomy (CPM). RESULTS: Between 2008 and 2010, we recruited 265 women. On the basis of intention-to-treat analyses, no significant group differences were observed in percentage of patients opting for a direct BLM (14.6% for the RGCT group vs 9.2% for the control group; odds ratio (OR) 2.31; confidence interval (CI) 0.92-5.81; P=0.08) or for a delayed CPM (4.5% for the RGCT group vs 5.7% for the control group; OR 0.89; CI 0.27-2.90; P=0.84). Per-protocol analysis indicated that patients who received DNA test results before surgery (59 out of 178 women in the RGCT group) opted for direct BLM significantly more often than patients who received usual care (22% vs 9.2%; OR 3.09, CI 1.15-8.31, P=0.03). INTERPRETATION: Although the large majority of patients in the intervention group underwent rapid genetic counselling, only a minority received DNA test results before surgery. This may explain why offering RGCT yielded only marginally significant differences in uptake of BLM. As patients who received DNA test results before surgery were more likely to undergo BLM, we hypothesise that when DNA test results are made routinely available pre-surgery, they will have a more significant role in surgical treatment decisions.

A novel missense mutation (N78D) in a family with von Hippel-Lindau disease with central nervous system haemangioblastomas, pancreatic and renal cysts.

von Hippel-Lindau (VHL) disease is a hereditary tumor syndrome caused by mutations in the VHL tumor suppressor gene. In a family with VHL, we identified a novel missense mutation (N78D), which affects a fully conserved residue in the VHL protein. Interestingly, several other missense mutations reported at same codon in the VHL protein that might be associated with a low risk of renal cell carcinoma (RCC) but not pheochromocytoma appear to be associated with a VHL type 1 phenotype. At the moment, RCC is present in none of the affected mutation carriers in the family described here. In contrast to other missense changes at codon 78, the change in our VHL family is predicted to have a mild effect on VHL function, which apparently is insufficient to cause predisposition to RCC. Our findings suggest that the risk of RCC in VHL is attributable to the severity of the amino acid substitution at this particular codon in the VHL protein.

Distress in partners of individuals diagnosed with or at high risk of developing tumors due to rare hereditary cancer syndromes.

OBJECTIVE: Li Fraumeni syndrome (LFS) and Von Hippel-Lindau disease (VHL) are two rare hereditary tumor syndromes, characterized by a high risk of developing multiple tumors at various sites and ages for which preventive and treatment options are limited. For partners, it may be difficult to deal with the on-going threat of tumors in both their spouse and children. Therefore, this study aims to evaluate the prevalence of and factors associated with psychological distress among partners of individuals with or at high risk of LFS or VHL. METHODS: As part of a nationwide, cross-sectional study, partners of individuals diagnosed with or at high risk of LFS or VHL were invited to complete a self-report questionnaire assessing distress, worries, and health-related quality of life. RESULTS: Fifty-five (58%) of those high-risk individuals with a partner consented to having their partner approached for the study. In total, 50 partners (91%) completed the questionnaire, of whom 28% reported clinically relevant levels of syndrome-related distress. Levels of distress and worries of the partners and their high-risk spouse were significantly correlated. Younger age and a lack of social support were also associated significantly with heightened levels of distress and worries. The majority of partners (76%) believed that professional psychosocial support should be routinely offered to them. CONCLUSIONS: Approximately one-quarter of the partners exhibit clinically relevant levels of distress that warrant psychological support. The distress levels of the 'patient' could potentially be used to identify partners at risk of developing clinically relevant levels of distress.

Care for patients with multiple endocrine neoplasia type 1: the current evidence base.

Multiple endocrine neoplasia type 1 (MEN1) is a rare disease caused by mutations in the MEN1 gene on chromosome 11. It is characterized by the occurrence of primary hyperparathyroidism (pHPT), duodenopancreatic neuroendocrine tumours (pNET), pituitary tumours (PIT), adrenal adenomas (ADR) and neuroendocrine tumours (NET) of the stomach, bronchus and thymus. MEN1 is a syndrome with high penetrance and high morbidity. Malignant NETs are the most important cause of MEN1-related death. Since 1997 the diagnosis can be made by genetic screening. MEN1 is a complex syndrome and the endocrine manifestations cannot be viewed upon as coinciding sporadic tumours. Differences in epidemiology and pathology between MEN1-related tumours and their sporadic counterparts show that a unique approach is needed. Therefore the care for MEN1 patients should be provided by a centre of expertise. Early genetic diagnosis and periodic screening are important pillars of care. For primary hyperparathyroidism surgery is the most important treatment modality, with a subtotal parathyroid gland resection as the procedure of choice. In neuroendocrine tumours surgery also is the most important treatment modality. Selective tumour enucleation has no place in the surgical treatment of MEN1-related pNETs; the exact procedure depends on the functionality of the tumour. In MEN1-associated pituitary and adrenal adenomas, watchful waiting and medical therapy play more important roles. In the twenty-first century new developments will impact the care for MEN1 patients. These developments should be critically evaluated in clinical research with the ultimate goal of optimizing the care for MEN1 patients on an evidence base.

Psychosocial impact of Von Hippel-Lindau disease: levels and sources of distress.

Von Hippel-Lindau disease (VHL) is a hereditary tumor susceptibility syndrome, characterized by an increased risk of developing multiple benign and malignant tumors at various sites and ages with limited preventive options. This study evaluates the prevalence of distress among VHL family members and factors associated significantly with such distress. Forty-eight families with a VHL mutation were identified via the nine family cancer clinics in the Netherlands. In total, 171 family members (carriers, 50% at-risk, non-carriers) were approached, of whom 123 (72%) completed a self-report questionnaire. Approximately 40% of the VHL family members reported clinically relevant levels of distress, approaching 50% among the carriers and, possibly even more striking, 36% among the non-carriers. Having lost a first degree relative due to VHL during adolescence (OR 11.2; 95% CI 1.4-86.9) was related significantly to heightened levels of distress. Approximately, only one-third of those who reported heightened levels of distress had received professional psychosocial support. A substantial percentage of family members experience clinically relevant levels of distress. We would recommend the introduction of a procedure for screening for distress in this vulnerable population. Special attention should be paid to those individuals who have lost a close relative due to VHL during adolescence.

Multiple endocrine neoplasia type 1 (MEN1): its manifestations and effect of genetic screening on clinical outcome.

OBJECTIVE: Effect of genetic screening on outcome in multiple endocrine neoplasia type 1 (MEN1) remains unclear. Expression of MEN1 is described using currently available diagnostic techniques. Manifestations and outcome are compared in patients diagnosed because of clinical expression with those diagnosed by genetic screening. DESIGN: Retrospective cohort study. Patients are divided into two groups: patients with a (i) clinical MEN1 diagnosis and (ii) MEN1 diagnosis by genetic screening. PATIENTS AND MEASUREMENTS: Demographic and clinical data were collected on MEN1 patients treated in the UMCU up to 1 January 2008. Results of mutation analysis were obtained from the Department of Medical Genetics. RESULTS: A total of 74 patients was included (median follow-up 5.5 year); 78% had hyperparathyroidism, 46% a pancreatic neuro-endocrine tumour (NET), 38% a pituitary abnormality, 8% a NET of other origin and 16% an adrenal adenoma at the end of follow-up. Of the patients 18% had no manifestation. All five MEN1-related tumours were seen as first manifestation. Compared with patients identified by genetic screening, patients with a clinical MEN1 diagnosis had significantly more manifestations at diagnosis (P < 0.001) and at end of follow-up (P = 0.002). Eleven of 30 patients with a genetic MEN1 diagnosis (mean age at diagnosis 30.0 years) already had manifestations at diagnosis. No malignancy or death was seen in genetically diagnosed patients. CONCLUSIONS: MEN1 is a syndrome with high morbidity. Genetic diagnosis is associated with less morbidity at diagnosis and at follow-up. Early genetic diagnosis might therefore lead to improvement of long-term outcome.

Frequency of Von Hippel-Lindau germline mutations in classic and non-classic Von Hippel-Lindau disease identified by DNA sequencing, Southern blot analysis and multiplex ligation-dependent probe amplification.

The current clinical diagnosis of Von Hippel-Lindau (VHL) disease demands at least one specific [corrected] VHL manifestation in a patient with familial VHL disease, or, in a [corrected] sporadic patient, at least two or more hemangioblastomas or a single hemangioblastoma in combination with a typical visceral lesion. To evaluate this definition, we studied the frequency of germline VHL mutation in three patients groups: (i) multi-organ involvement (classic VHL), (ii) limited VHL manifestations meeting criteria (non-classic VHL) and (iii) patients with VHL-associated tumors not meeting current diagnostic VHL criteria. In addition, we validated multiplex ligation-dependent probe amplification (MLPA) as a rapid and reliable quantitative method for the identification of germline VHL deletions. The frequency of germline VHL mutations was very high in classic VHL cases with multi-organ involvement (95%), lower in non-classic cases that meet current diagnostic criteria but have limited VHL manifestations or single-organ involvement (24%) and low (3.3%), but tangible in cases not meeting current diagnostic VHL criteria. The detection of germline VHL mutations in patients or families with limited VHL manifestations, or single-organ involvement is relevant for follow-up of probands and early identification of at-risk relatives.

Rapid detection of chromosomal aneuploidies in uncultured amniocytes by multiplex ligation-dependent probe amplification (MLPA).

OBJECTIVE: To test whether multiplex ligation-dependent probe amplification (MLPA) can be used for the detection of aneuploidy of chromosomes 13, 18, 21, X, and Y in uncultured amniocytes. METHODS: We performed a prospective study based on 527 amniotic fluid samples. Chromosome copy numbers were determined by analysing the relative amount of PCR product of chromosome-specific MLPA probes. Results were available within 48 h and were compared with those of karyotyping. RESULTS: There were 517 conclusive MLPA tests. In 514 tests, results were concordant with those of karyotyping. There were two cases of 69,XXX triploidy that could not be detected by MLPA and there was one false-positive result. Here, MLPA indicated a 47,XXY fetus, whereas the karyotype was 46,XY. We correctly identified all 23 cases of autosomal trisomy and the single case of monosomy X in samples collected from 16 up to 36 weeks of gestation. In 10 cases (2%), the result was inconclusive owing to an insufficient amount of DNA. CONCLUSION: Sensitivity, specificity, and failure rate of MLPA were comparable to those of FISH and QF-PCR. Aneuploidy screening in uncultured amniocytes by MLPA is feasible in a clinical diagnostic setting, yielding an informative and rapid result in 98% of cases.

Classification of BRCA1 missense variants of unknown clinical significance.

BACKGROUND: BRCA1 is a tumour suppressor with pleiotropic actions. Germline mutations in BRCA1 are responsible for a large proportion of breast-ovarian cancer families. Several missense variants have been identified throughout the gene but because of lack of information about their impact on the function of BRCA1, predictive testing is not always informative. Classification of missense variants into deleterious/high risk or neutral/low clinical significance is essential to identify individuals at risk. OBJECTIVE: To investigate a panel of missense variants. METHODS AND RESULTS: The panel was investigated in a comprehensive framework that included (1) a functional assay based on transcription activation; (2) segregation analysis and a method of using incomplete pedigree data to calculate the odds of causality; (3) a method based on interspecific sequence variation. It was shown that the transcriptional activation assay could be used as a test to characterise mutations in the carboxy-terminus region of BRCA1 encompassing residues 1396-1863. Thirteen missense variants (H1402Y, L1407P, H1421Y, S1512I, M1628T, M1628V, T1685I, G1706A, T1720A, A1752P, G1788V, V1809F, and W1837R) were specifically investigated. CONCLUSIONS: While individual classification schemes for BRCA1 alleles still present limitations, a combination of several methods provides a more powerful way of identifying variants that are causally linked to a high risk of breast and ovarian cancer. The framework presented here brings these variants nearer to clinical applicability.

Counselling in multiple endocrine neoplasia syndromes: from individual experience to general guidelines.

Counselling of patients and closely related family members has to take a central place in management of hereditary diseases, like multiple endocrine neoplasia (MEN) syndromes including von Hippel-Lindau (VHL) disease. In the strategy of health care, preventive medicine such as periodic clinical examination of families at-risk needs a high priority, because in general it is assumed that continuity in attendance is cost-effective. Counselling has to be based on individual medical experience of the doctor, adjusted to common guidelines and the findings in the family. Information leaflets, appropriate outpatient departments and an extensive network of specialists will facilitate continuity in care. Flow diagrams involving practical guidelines for diagnosis, treatment and follow up need to be applicable and after adjustment, should be accepted generally. Specially trained paramedics for counselling are required as a network that will guarantee periodic clinical examination and secure optimal prevention. Such paramedics will coordinate nationwide multidisciplinary guidance, and organize preventive and emergency cure for these patients. They will be supervised by expert clinicians in the field, and collaborate with specialists for social and psychological issues, patient organizations and clinical genetic centres. All of these professionals are responsible together for providing patients with up to date clinical information (via newsletters, Internet, etc.). Recently, in the Netherlands, a project was initiated to guarantee continuity in care and study the delivery of care. In order to realize this plan, funding has to be provided in the current research programme. In a future system support has to be obtained on a continuous base, preferably by the government and health care insurers and supervised by the national institute for health care.

Earliest gestational age for fetal sexing in cell-free maternal plasma.

OBJECTIVES: To evaluate at what gestational age fetal DNA can reliably be detected at the earliest in maternal plasma. METHODS: We performed consecutive blood sampling in the first trimester of pregnancy in 17 women who were pregnant after in vitro fertilization (IVF) or intrauterine insemination (IUI). DNA was isolated and the Y-chromosome specific SRY was amplified by real-time polymerase chain reaction (PCR). We likewise studied 31 women prior to invasive prenatal diagnosis procedures for test validation purposes. All test results were compared to cytogenetic sex or sex at birth. RESULTS: The earliest SRY detection was at a gestational age of 5 weeks and 2 days. In none of 4 pregnancies ending in a miscarriage was SRY detected. We detected SRY in maternal plasma in 1 of 2 patients (50%) carrying a male fetus at a gestational age of 5 weeks, in 4 of 5 (80%) at a gestational age of 7 weeks, in 4 of 4 (100%) at a gestational age of 9 weeks. In all 7 women pregnant with a male fetus, the correct fetal sex was detected by 10 weeks. In none of the 6 patients who delivered a girl was SRY detected. In the validation group, SRY was detected in 13 of the 13 male, and none of the 18 female fetuses. CONCLUSIONS: We conclude that real-time PCR of the SRY gene promises to be a reliable technique for early fetal sexing in maternal plasma.

[From gene to disease; Von Hippel-Lindau disease]. / Van gen naar ziekte; de ziekte van Von Hippel-Lindau.

Von Hippel-Lindau (VHL) disease is an autosomal, dominantly inherited, tumour syndrome. Carriers of a germline mutation in the VHL tumour suppressor genes are predisposed to develop tumours in various organs including the eye, cerebellum and kidney. These tumours are often multicentric or bilateral, and manifest at a younger age than in situations without a VHL germline mutation. VHL germline mutations are identified in virtually all families and sporadic patients with classic VHL disease. VHL associated tumours are richly vascularised. This is consistent with the involvement of the VHL protein in multiprotein complexes that degrade hypoxia-inducible factors dependent on cellular oxygen levels.

A novel germline mutation of PTEN associated with brain tumours of multiple lineages.

We have identified a novel germline mutation in the PTEN tumour suppressor gene. The mutation was identified in a patient with a glioma, and turned out to be a heterozygous germline mutation of PTEN (Arg234Gln), without loss of heterozygosity in tumour DNA. The biological consequences of this germline mutation were investigated by means of transfection studies of the mutant PTEN molecule compared to wild-type PTEN. In contrast to the wild-type molecule, the mutant PTEN protein is not capable of inducing apoptosis, induces increased cell proliferation and leads to high constitutive PKB/Akt activation, which cannot be increased anymore by stimulation with insulin. The reported patient, in addition to glioma, had suffered from benign meningioma in the past but did not show any clinical signs of Cowden disease or other hereditary diseases typically associated with PTEN germline mutations. The functional consequences of the mutation in transfection studies are consistent with high proliferative activity. Together, these findings suggest that the Arg234Gln missense mutation in PTEN has oncogenic properties and predisposes to brain tumours of multiple lineages.

Clinical management of Von Hippel-Lindau (VHL) disease.

Von Hippel-Lindau (VHL) disease is an autosomal, dominant inherited tumour syndrome with an estimated prevalence of 2-3 per 100,000 persons. A germline mutation in the VHL gene predisposes carriers to tumours in multiple organs. These tumours may include haemangioblastoma in the retina and central nervous system (CNS), renal cell carcinoma, phaeochromocytoma, islet cell tumours of the pancreas, and endolymphatic sac tumours, as well as cysts and cystadenoma in the kidney, pancreas, epididymis and broad ligament. Penetrance of VHL disease is high, most carriers of a VHL germline mutation develop one or more tumours by the age of 60 years. The most common symptoms include: loss of vision, raised intracranial pressure, neurological deficits, paroxysmal raised blood pressure and local pain. At present, metastases from renal cell carcinoma and neurological complications from cerebellar haemangioblastoma are the most common causes of death. However, it is anticipated that intensive radiological and clinical monitoring, and advanced operation techniques will reduce both morbidity and mortality in patients with VHL disease.

Molecular genetic aspects of Von Hippel-Lindau (VHL) disease and criteria for DNA analysis in subjects at risk.

Von Hippel-Lindau (VHL) disease is an autosomal, dominantly inherited tumour syndrome. Carriers of a germline mutation in the VHL tumour suppressor gene tumours are predisposed to develop tumours that are multicentric or bilateral, and manifest at a younger age than in situations without a VHL germline mutation. The mutation spectrum is heterogeneous, with mutations scattered throughout most of the VHL gene. Although some recurrent mutations have been reported, most families have their own unique germline mutation. Tested individuals are no longer uncertain regarding their risk for developing the disease and family members who are non-carriers are relieved of the burden of repeated clinical monitoring.VHL germline mutations are identified in virtually all families and sporadic patients with classic VHL disease, but also in patients who do not meet clinical diagnostic criteria. The chance of finding a VHL germline mutation in (apparently) sporadic patients not fulfilling the criteria increases with: young age at diagnosis, the presence of multi-centric or bilateral tumours, involvement of multiple organs and a positive family history of VHL associated tumours.

[From gene to disease; from the RET gene to multiple endocrine neoplasia types 2A and 2B, sporadic and familial medullary thyroid carcinoma, Hirschsprung disease and papillary thyroid carcinoma]. / Van gen naar ziekte; van het RET-gen naar multipele endocriene neoplasie type 2A en 2B, sporadisch en familiair medullair schildkliercarcinoom, ziekte van Hirschsprung en papillair schildkliercarcinoom.

The RET gene encodes a receptor tyrosine kinase involved in normal and neoplastic development of neural crest cell lineages. Activating RET mutations are present in patients with multiple endocrine neoplasia types 2A and 2B (MEN2A, 2B) and in familial medullary thyroid carcinoma (FMTC) patients, whereas inactivating RET mutations are found in patients with Hirschsprung (HSCR) disease. In particular for MEN2A and FMTC, the clinical management largely depends on the specific mutation found.

[From gene to disease; the APC gene and familial adenomatous polyposis coli]. / Van gen naar ziekte; het APC-gen en familiaire adenomateuze polyposis.

Familial adenomatous polyposis coli is an autosomal dominant hereditary form of colorectal cancer associated with mutations in the adenomatous polyposis coli (APC) gene on chromosome 5. The APC protein is thought to mediate the stability of beta-catenin in the WNT signaling transduction pathway ('wingless-type mouse mammary tumor virus integration site family member') in normal colonic epithelial cells, thereby indirectly regulating the expression of WNT target genes such as the c-myc-oncogene. APC gene mutations cause the development of multiple adenomatous polyps in the colorectum, which strongly predisposes gene carriers to colorectal cancer. Extracolonic manifestations, including gastric and duodenal polyps, osteomas, desmoids, epidermoid cysts, and retinal lesions, are commonly observed in patients with familial adenomatous polyposis. Detection of mutations in the APC gene allows genetic counselling and reliable identification of at-risk individuals.

Criteria for mutation analysis in MEN 1-suspected patients: MEN 1 case-finding.

BACKGROUND: Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal, dominantly inherited cancer syndrome, with tumours in various endocrine glands. In 1997 the responsible tumour suppressor gene was identified. MEN1 gene germ-line mutations are detected in the vast majority of MEN 1 patients, however, with regard to case-finding, unfortunately only at a very low frequency in patients with apparently sporadic MEN 1-related tumours. In order to increase the detection rate of disease gene carriers among patients with apparently sporadic MEN 1-related tumours, clinical criteria were needed. DESIGN AND RESULTS: In this study MEN1 gene germ-line mutations were revealed in 16/16 MEN 1 patients/families (100%). Based on our clinical experience with MEN 1 patients/families we formulated clinical criteria to identify disease gene carriers among patients with apparently sporadic MEN 1-related tumours. The criteria for MEN 1-suspected patients are: young age at onset (< 35 years) and/or multiple MEN 1-related lesions in a single organ or two distinct organs affected. Application of these criteria yielded MEN1 gene germ-line mutations in nine of 15 MEN 1-suspected patients (60%), thus identifying novel MEN 1 families. Follow up was also guaranteed for patients not fulfilling these criteria. CONCLUSIONS: The clinical criteria for MEN 1-suspected patients increase the detection rate of germ-line MEN1 gene mutations among patients with apparently sporadic MEN 1-related tumours. These criteria may be used for (presymptomatic) identification of MEN 1 disease gene-carriers, thus enabling early detection of tumour development and timely treatment, as well as genetic counselling.

Genotype-phenotype correlations in families with deletions in the von Hippel-Lindau (VHL) gene.

Von Hippel-Lindau (VHL) disease is a hereditary tumor syndrome characterized by predisposition for bilateral and multi-centric hemangioblastoma in the retina and central nervous system, pheochromocytoma, renal cell carcinoma, and cysts in the kidney, pancreas, and epididymis. We describe five families for which direct sequencing of the coding region of the VHL gene had failed to identify the family-specific mutation. Further molecular analysis revealed deletions involving the VHL gene in each of these families. In four families, partial deletions of one or more exons were detected by Southern blot analysis. In the fifth family, FISH analysis demonstrated the deletion of the entire VHL gene. Our results show that (quantitative) Southern blot analysis is a sensitive method for detecting germline deletions of the VHL gene and should be implemented in routine DNA diagnosis for VHL disease. Our data support the previously established observation that families with a germline deletion have a low risk for pheochromocytoma. Further unraveling of genotype-phenotype correlations in VHL disease has revealed that families with a full or partial deletion of the VHL gene exhibit a phenotype with a preponderance of central nervous system hemangioblastoma.