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Open access

Gemma White, Nicola Tufton and Scott A Akker

Summary

At least 40% of phaeochromocytomas and paraganglioma’s (PPGLs) are associated with an underlying genetic mutation. The understanding of the genetic landscape of these tumours has rapidly evolved, with 18 associated genes now identified. Among these, mutations in the subunits of succinate dehydrogenase complex (SDH) are the most common, causing around half of familial PPGL cases. Occurrence of PPGLs in carriers of SDHB, SDHC and SDHD subunit mutations has been long reported, but it is only recently that variants in the SDHA subunit have been linked to PPGL formation. Previously documented cases have, to our knowledge, only been found in isolated cases where pathogenic SDHA variants were identified retrospectively. We report the case of an asymptomatic suspected carotid body tumour found during surveillance screening in a 72-year-old female who is a known carrier of a germline SDHA pathogenic variant. To our knowledge, this is the first screen that detected PPGL found in a previously identified SDHA pathogenic variant carrier, during surveillance imaging. This finding supports the use of cascade genetic testing and surveillance screening in all carriers of a pathogenic SDHA variant.

Learning points:

  • SDH mutations are important causes of PPGL disease.

  • SDHA is much rarer compared to SDHB and SDHD mutations.

  • Pathogenicity and penetrance are yet to be fully determined in cases of SDHA-related PPGL.

  • Surveillance screening should be used for SDHA PPGL cases to identify recurrence, metastasis or metachronous disease.

  • Surveillance screening for SDH-related disease should be performed in identified carriers of a pathogenic SDHA variant.

Open access

Yang Timothy Du, Lynette Moore, Nicola K Poplawski and Sunita M C De Sousa

Summary

A 26-year-old man presented with a combination of permanent neonatal diabetes due to pancreatic aplasia, complex congenital heart disease, central hypogonadism and growth hormone deficiency, structural renal abnormalities with proteinuria, umbilical hernia, neurocognitive impairment and dysmorphic features. His older brother had diabetes mellitus due to pancreatic hypoplasia, complex congenital heart disease, hypospadias and umbilical hernia. Their father had an atrial septal defect, umbilical hernia and diabetes mellitus diagnosed incidentally in adulthood on employment screening. The proband’s paternal grandmother had a congenital heart defect. Genetic testing of the proband revealed a novel heterozygous missense variant (Chr18:g.19761441T>C, c.1330T>C, p.Cys444Arg) in exon 4 of GATA6, which is class 5 (pathogenic) using American College of Medical Genetics and Genomics guidelines and is likely to account for his multisystem disorder. The same variant was detected in his brother and father, but not his paternal grandmother. This novel variant of GATA6 likely occurred de novo in the father with autosomal dominant inheritance in the proband and his brother. The case is exceptional as very few families with monogenic diabetes due to GATA6 mutations have been reported to date and we describe a new link between GATA6 and renal pathology.

Learning points:

  • Monogenic diabetes should be suspected in patients presenting with syndromic features, multisystem congenital disease, neonatal-onset diabetes and/or a suggestive family history.

  • Recognition and identification of genetic diabetes may improve patient understanding and empowerment and allow for better tailored management.

  • Identification of a genetic disorder may have important implications for family planning.

Open access

Athanasios Fountas, Zoe Giotaki, Evangelia Dounousi, George Liapis, Alexandra Bargiota, Agathocles Tsatsoulis and Stelios Tigas

Summary

Proteinuric renal disease is prevalent in congenital or acquired forms of generalized lipodystrophy. In contrast, an association between familial partial lipodystrophy (FPLD) and renal disease has been documented in very few cases. A 22-year-old female patient presented with impaired glucose tolerance, hyperinsulinemia, hirsutism and oligomenorrhea. On examination, there was partial loss of subcutaneous adipose tissue in the face, upper and lower limbs, bird-like facies with micrognathia and low set ears and mild acanthosis nigricans. Laboratory investigations revealed hyperandrogenism, hyperlipidemia, elevated serum creatine kinase and mild proteinuria. A clinical diagnosis of FPLD of the non-Dunnigan variety was made; genetic testing revealed a heterozygous c.1045C > T mutation in exon 6 of the LMNA gene, predicted to result in an abnormal LMNA protein (p.R349W). Electromyography and muscle biopsy were suggestive of non-specific myopathy. Treatment with metformin and later with pioglitazone was initiated. Due to worsening proteinuria, a renal biopsy was performed; histological findings were consistent with mild focal glomerular mesangioproliferative changes, and the patient was started on angiotensin-converting enzyme inhibitor therapy. This is the fourth report of FPLD associated with the c.1045C > T missense LMNA mutation and the second with co-existent proteinuric renal disease. Patients carrying this specific mutation may exhibit a phenotype that includes partial lipodystrophy, proteinuric nephropathy, cardiomyopathy and atypical myopathy.

Learning points:

  • Lipodystrophy is a rare disorder characterized by the complete or partial loss of subcutaneous adipose tissue, insulin resistance, diabetes mellitus and hyperlipidemia.

  • Proteinuric renal disease is a prevalent feature of generalized lipodystrophy but rare in familial partial lipodystrophy.

  • Patients carrying the c.1045C > T missense LMNA mutation (p.R349W) may present with familial partial lipodystrophy, proteinuric nephropathy, cardiomyopathy and atypical myopathy.

Open access

Kohei Saitoh, Takako Yonemoto, Takeshi Usui, Kazuhiro Takekoshi, Makoto Suzuki, Yoshiharu Nakashima, Koji Yoshimura, Rieko Kosugi, Tatsuo Ogawa and Tatsuhide Inoue

Summary

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare tumours with a heterogeneous genetic background. Up to 40% of apparently sporadic PCC/PGL cases carry 1 of the 12 gene germline mutations conferring genetic susceptibility to PCC/PGL. Although the precise mechanisms are unclear, TMEM127 is one of the rare responsible genes for PCC/PGL. Here we report the case of a patient with familial PCC having a novel TMEM127 variant (c.119C > T, p.S40F). In silico prediction analysis to evaluate the functional significance of this variant suggested that it is a disease-causing variant. A PCC on the left side was considered to be the dominant lesion, and unilateral adrenalectomy was performed. The histopathologic findings were consistent with benign PCC. A loss of heterogeneity of the TMEM127 variant was detected in the surgically removed tumour.

Learning points:

  • c.119C > T (p.S40F) is a novel TMEM127 variant that can cause pheochromocytoma.

  • The tumour showed loss of heterozygosity of this TMEM127 variant.

  • The clinical phenotype of this mutation is putative bilateral pheochromocytoma in the 4th decade.

  • Unilateral adrenalectomy may be performed as the initial surgery in such cases.

Open access

Teresa Rego, Fernando Fonseca, Stéphanie Espiard, Karine Perlemoine, Jérôme Bertherat and Ana Agapito

Summary

PBMAH is a rare etiology of Cushing syndrome (CS). Familial clustering suggested a genetic cause that was recently confirmed, after identification of inactivating germline mutations in armadillo repeat-containing 5 (ARMC5) gene. A 70-year-old female patient was admitted due to left femoral neck fracture in May 2014, in Orthopedics Department. During hospitalization, hypertension (HTA) and hypokalemia were diagnosed. She presented with clinical signs of hypercortisolism and was transferred to the Endocrinology ward for suspected CS. Laboratory workup revealed: ACTH <5 pg/mL; urinary free cortisol (UFC), 532 µg/24 h (normal range: 20–90); failure to suppress the low-dose dexamethasone test (0.5 mg every 6 h for 48 h): cortisol 21 µg/dL. Abdominal magnetic resonance imaging (MRI) showed enlarged nodular adrenals (right, 55 × 54 × 30 mm; left, 85 × 53 × 35 mm), and she was submitted to bilateral adrenalectomy. In 2006, this patient’s 39-year-old daughter had been treated by one of the authors. She presented with severe clinical and biological hypercortisolism. Computed tomography (CT) scan showed massively enlarged nodular adrenals with maximal axis of 15 cm for both. Bilateral adrenalectomy was performed. In this familial context of PBMAH, genetic study was performed. Leucocyte DNA genotyping identified in both patients the same germline heterozygous ARMC5 mutation in exon 1 c.172_173insA p.I58Nfs*45. The clinical cases herein described have an identical phenotype with severe hypercortisolism and huge adrenal glands, but different ages at the time of diagnosis. Current knowledge of inheritance of this disease, its insidious nature and the well-known deleterious effect of hypercortisolism favor genetic study to timely identify and treat these patients.

Learning points:

  • PBMAH is a rare etiology of CS, characterized by functioning adrenal macronodules and variable cortisol secretion.

  • The asymmetric/asynchronous involvement of only one adrenal gland can also occur, making disease diagnosis a challenge.

  • Familial clustering suggests a genetic cause that was recently confirmed, after identification of inactivating germline mutations in armadillo repeat-containing 5 (ARMC5) gene.

  • The insidious nature of this disease and the well-known deleterious effect of hypercortisolism favor genetic study of other family members, to diagnose and treat these patients timely.

  • As ARMC5 is expressed in many organs and recent findings suggest an association of PBMAH and meningioma, a watchful follow-up is required.

Open access

Durgesh Prasad Chaudhary, Tshristi Rijal, Kunal Kishor Jha and Harpreet Saluja

Summary

Combined pituitary hormonal deficiency (CPHD) is a rare disease that results from mutations in genes coding for transcription factors that regulate the differentiation of pituitary cells. PROP1 gene mutations are one of the etiological diagnoses of congenital panhypopituitarism, however symptoms vary depending on phenotypic expression. We present a case of psychosis in a 36-year-old female with congenital panhypopituitarism who presented with paranoia, flat affect and ideas of reference without a delirious mental state, which resolved with hormone replacement and antipsychotics. Further evaluation revealed that she had a homozygous mutation of PROP1 gene. In summary, compliance with hormonal therapy for patients with hypopituitarism appears to be effective for the prevention and treatment of acute psychosis symptoms.

Learning points:

  • Patients with PROP1 gene mutation may present with psychosis with no impairment in orientation and memory.

  • There is currently inadequate literature on this topic, and further study on the possible mechanisms of psychosis as a result of endocrine disturbance is required.

  • Compliance with hormonal therapy for patients with hypopituitarism appears to be effective for prevention and treatment of acute psychosis symptoms.

Open access

Rowena Speak, Jackie Cook, Barney Harrison and John Newell-Price

Mutations of the rearranged during transfection (RET) proto-oncogene, located on chromosome 10q11.2, cause multiple endocrine neoplasia type 2A (MEN2A). Patients with mutations at the codon 609 usually exhibit a high penetrance of medullary thyroid cancer (MTC), but a sufficiently low penetrance of phaeochromocytoma that screening for this latter complication has been called to question. Patients with other RET mutations are at higher risk of younger age onset phaeochromocytoma if they also possess other RET polymorphisms (L769L, S836S, G691S and S904S), but there are no similar data for patients with 609 mutations. We investigated the unusual phenotypic presentation in a family with MEN2A due to a C609Y mutation in RET. Sanger sequencing of the entire RET-coding region and exon–intron boundaries was performed. Five family members were C609Y mutation positive: 3/5 initially presented with phaeochromocytoma, but only 1/5 had MTC. The index case aged 73 years had no evidence of MTC, but presented with phaeochromocytoma. Family members also possessed the G691S and S904S RET polymorphisms. We illustrate a high penetrance of phaeochromocytoma and low penetrance of MTC in patients with a RET C609Y mutation and polymorphisms G691S and S904S. These data highlight the need for life-long screening for the complications of MEN2A in these patients and support the role for the screening of RET polymorphisms for the purposes of risk stratification.

Learning points:

  • C609Y RET mutations may be associated with a life-long risk of phaeochromocytoma indicating the importance of life-long screening for this condition in patients with MEN2A.

  • C609Y RET mutations may be associated with a lower risk of MTC than often quoted, questioning the need for early prophylactic thyroid surgery discussion at the age of 5 years.

  • There may be a role for the routine screening of RET polymorphisms, and this is greatly facilitated by the increasing ease of access to next-generation sequencing.

Open access

Jin-Ying Lu, Po-Ju Hung, Pei-Lung Chen, Ruoh-Fang Yen, Kuan-Ting Kuo, Tsung-Lin Yang, Chih-Yuan Wang, Tien-Chun Chang, Tien-Shang Huang and Ching-Chung Chang

Summary

We report a case of follicular thyroid carcinoma with concomitant NRAS p.Q61K and GNAS p.R201H mutations, which manifested as a 13.5 cm thyroid mass with lung, humerus and T9 spine metastases, and exhibited good response to radioactive iodine treatment.

Learning points

  • GNAS p.R201H somatic mutation is an activating or gain-of-function mutation resulting in constitutively activated Gs-alpha protein and downstream cAMP cascade, independent of TSH signaling, causing autonomously functioning thyroid nodules.

  • NRAS p.Q61K mutations with GNAS p.R201H mutations are known for a good radioactive iodine treatment response.

  • Further exploration of the GNAS-activating pathway may provide therapeutic insights into the treatment of metastatic follicular carcinoma.

Open access

Asma Deeb, Hana Al Suwaidi, Salima Attia and Ahlam Al Ameri

Summary

Combined17α-hydroxylase/17,20-lyase deficiency is a rare cause of congenital adrenal hyperplasia and hypogonadism. Hypertension and hypokalemia are essential presenting features. We report an Arab family with four affected XX siblings. The eldest presented with abdominal pain and was diagnosed with a retroperitoneal malignant mixed germ cell tumour. She was hypertensive and hypogonadal. One sibling presented with headache due to hypertension while the other two siblings were diagnosed with hypertension on a routine school check. A homozygous R96Q missense mutation in P450c17 was detected in the index case who had primary amenorrhea and lack of secondary sexual characters at 17 years. The middle two siblings were identical twins and had no secondary sexual characters at the age of 14. All siblings had hypokalemia, very low level of adrenal androgens, high ACTH and high levels of aldosterone substrates. Treatment was commenced with steroid replacement and puberty induction with estradiol. The index case had surgical tumor resection and chemotherapy. All siblings required antihypertensive treatment and the oldest remained on two antihypertensive medications 12 years after diagnosis. Her breast development remained poor despite adequate hormonal replacement. Combined 17α-hydroxylase/17,20-lyase deficiency is a rare condition but might be underdiagnosed. It should be considered in young patients presenting with hypertension, particularly if there is a family history of consanguinity and with more than one affected sibling. Antihypertensive medication might continue to be required despite adequate steroid replacement. Breast development may remain poor in mutations causing complete form of the disease.

Learning points

  • Endocrine hypertension due to rarer forms of CAH should be considered in children and adolescents, particularly if more than one sibling is affected and in the presence of consanguinity.

  • 17α-hydroxylase/17,20-lyase deficiency is a rare form of CAH but might be underdiagnosed.

  • Blood pressure measurement should be carried out in all females presenting with hypogonadism.

  • Anti-hypertensive medications might be required despite adequate steroid replacement.

  • Initial presenting features might vary within affected members of the same family.

  • Adverse breast development might be seen in the complete enzyme deficiency forms of the disease.

Open access

Avinash Suryawanshi, Timothy Middleton and Kirtan Ganda

Summary

X-linked adrenoleukodystrophy (X-ALD) is a rare genetic condition caused by mutations in the ABCD1 gene that result in accumulation of very long chain fatty acids (VLCFAs) in various tissues. This leads to demyelination in the CNS and impaired steroidogenesis in the adrenal cortex and testes. A 57-year-old gentleman was referred for the assessment of bilateral gynaecomastia of 6 months duration. He had skin hyperpigmentation since 4 years of age and spastic paraparesis for the past 15 years. Physical examination findings included generalised hyperpigmentation (including skin, buccal mucosa and palmar creases), blood pressure of 90/60 mmHg, non-tender gynaecomastia and bilateral hypoplastic testes. Lower limb findings were those of a profoundly ataxic gait associated with significant paraparesis and sensory loss. Primary adrenal insufficiency was confirmed and investigations for gynaecomastia revealed normal testosterone with mildly elevated luteinising hormone level and normal prolactin. The combination of primary adrenal insufficiency (likely childhood onset), partial testicular failure (leading to gynaecomastia) and spastic paraparesis suggested X-ALD as a unifying diagnosis. A serum VLCFA panel was consistent with X-ALD. Subsequent genetic testing confirmed the diagnosis. Treatment with replacement doses of corticosteroid resulted in improvement in blood pressure and increased energy levels. We have reported the case of a 57-year-old man with a very late diagnosis of X-ALD manifested by childhood onset of primary adrenal insufficiency followed by paraparesis and primary hypogonadism in adulthood. Thus, X-ALD should be considered as a possibility in a patient with non-autoimmune primary adrenal insufficiency and neurological abnormalities.

Learning points

  • Adult patients with X-ALD may be misdiagnosed as having multiple sclerosis or idiopathic spastic paraparesis for many years before the correct diagnosis is identified.

  • Screening for X-ALD with a VLCFA panel should be strongly considered in male children with primary adrenal insufficiency and in male adults presenting with non-autoimmune primary adrenal insufficiency.

  • Confirmation of a genetic diagnosis of X-ALD can be very useful for a patient's family as genetic testing enables detection of pre-symptomatic female heterozygotes who can then be offered pre-natal testing to avoid transmission of the disease to male offsprings.