Browse

You are looking at 1 - 4 of 4 items for :

Clear All
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

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

Maria Pikilidou, Maria Yavropoulou and Marios Katsounaros

Summary

We report a case of a female with hemihypertrophy, who developed five recurrences of pheochromocytomas until the age of 35. Timely follow-up of the patient's blood pressure assisted in early diagnosis and treatment of recurrent tumors.

Learning points

  • Recurrent benign pheochromocytomas should raise suspicion of a genetic syndrome.

  • A pheochromocytoma at a young age has a high propensity to recur and strict follow-up is mandatory.

Open access

R Casey, S Prendeville, C Joyce and D O'Halloran

Summary

We present the case of a 30-year-old female who was diagnosed with hereditary phaeochromocytoma secondary to a rare gene mutation in exon 8 of the RET oncogene. This genetic mutation was picked up as part of an extended genetic screen using a method known as next generation sequencing. Detection of this genetic mutation prompted further screening for the manifestation of multiple endocrine neoplasia type 2A (MEN2A). The patient subsequently underwent a thyroidectomy with histology confirming C-cell hyperplasia.

Learning points

  • Genetic analysis is an important step in the diagnostic work up of phaeochromocytoma.

  • Extended genetic analysis is important when there is a strong suspicion of hereditary phaeochromocytoma.

  • Mutations in exon 8 of the RET gene are associated with phaeochromocytoma as part of MEN2A syndrome.