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Open access

Syed Ali Imran, Khaled A Aldahmani, Lynette Penney, Sidney E Croul, David B Clarke, David M Collier, Donato Iacovazzo and Márta Korbonits

Summary

Early-onset acromegaly causing gigantism is often associated with aryl-hydrocarbon-interacting receptor protein (AIP) mutation, especially if there is a positive family history. A15y male presented with tiredness and visual problems. He was 201 cm tall with a span of 217 cm. He had typical facial features of acromegaly, elevated IGF-1, secondary hypogonadism and a large macroadenoma. His paternal aunt had a history of acromegaly presenting at the age of 35 years. Following transsphenoidal surgery, his IGF-1 normalized and clinical symptoms improved. He was found to have a novel AIP mutation destroying the stop codon c.991T>C; p.*331R. Unexpectedly, his father and paternal aunt were negative for this mutation while his mother and older sister were unaffected carriers, suggesting that his aunt represents a phenocopy.

Learning points:

  • Typical presentation for a patient with AIP mutation with excess growth and eunuchoid proportions.
  • Unusual, previously not described AIP variant with loss of the stop codon.
  • Phenocopy may occur in families with a disease-causing germline mutation.
Open access

Jordan Yardain Amar, Kimberly Borden, Elizabeth Watson and Talin Arslanian

Summary

Isolated Growth Hormone Deficiency (IGHD) is a rare cause of short stature, treated with the standard regimen of subcutaneous synthetic growth hormone (GH). Patients typically achieve a maximum height velocity in the first year of treatment, which then tapers shortly after treatment is stopped. We report a case of a 9-year-old male who presented with short stature (<3rd percentile for age and race). Basal hormone levels showed undetectable serum IGF1. Skeletal wrist age was consistent with chronologic age. Cranial MRI revealed no masses or lesions. Provocative arginine-GH stimulation testing demonstrated a peak GH level of 1.4 ng/mL. Confirmatory genetic testing revealed a rare autosomal recessive single-nucleotide polymorphism (SNP) with mutational frequency of 2%. GH supplementation was started and pursued for 2 years, producing dramatically increased height velocity. This velocity persisted linearly through adolescence, several years after treatment had been discontinued. Final adult height was >95th percentile for age and race. In conclusion, this is a case of primary hypopituitarism with differential diagnosis of IGHD vs Idiopathic Short Stature vs Constitutional Growth Delay. This case supports two objectives: Firstly, it highlights the importance of confirmatory genetic testing in patients with suspected, though diagnostically uncertain, IGHD. Secondly, it demonstrates a novel secondary growth pattern with implications for better understanding the tremendous variability of GH treatment response.

Learning points:

  • GHD is a common cause of growth retardation, and IGHD is a specific subtype of GHD in which patients present solely with short stature.
  • The standard treatment for IGHD is subcutaneous synthetic GH until mid-parental height is reached, with peak height velocity attained in the 1st year of treatment in the vast majority of patients.
  • Genetic testing should be strongly considered in cases of diagnostic uncertainty prior to initiating treatment.
  • Future investigations of GH treatment response that stratify by gene and specific mutation will help guide treatment decisions.
  • Response to treatment in patients with IGHD is variable, with some patients demonstrating little to no response, while others are ‘super-responders.’
Open access

Bronwen E Warner, Carol D Inward and Christine P Burren

Summary

This case, presenting with bilateral impalpable testes, illustrates the relevance of a broad differential disorders of sex development case management. It provides new insights on hypothalamic–pituitary–gonadal (HPG) axis and testicular function abnormalities in the multisystem disorder of Lowe syndrome. Lowe syndrome, also known as oculocerebrorenal syndrome, is a rare disorder characterised by eye abnormalities, central nervous system involvement and proximal renal tubular acidosis. There are a handful of reports of pubertal delay, infertility and cryptorchidism in Lowe syndrome. Biochemistry aged 72 h: testosterone 6.4 nmol/L, LH <0.5 IU/L and FSH <0.5 IU/L. Gonadotropin-releasing hormone stimulation test identified significantly raised baseline LH = 45.4 IU/L (contrasts with earlier undetectable LH), with a 20% increase on stimulation, while baseline FSH = 4.3 IU/L with no increase on stimulation. Day 14 HCG stimulation test produced an acceptable 50% increase in testosterone. The constellation of further abnormalities suggested Lowe syndrome: hypotonia, bilateral cataracts (surgical extraction and intraocular lens implantation) and renal tubular acidosis (microscopic haematuria, hypercalciuria, proteinuria, generalised aminoaciduria, hypophosphataemia and metabolic acidosis). DNA sequencing identified de novo hemizygous frameshift mutation OCRL c.2409_2410delCT in exon 22. Interpretation of initial and repeat GnRH and HCG testing indicates the likelihood of testicular failure. Partial testicular descent occurred but left orchidopexy was required. Improving long-term gonadal function in Lowe syndrome assumes increased importance for current cohorts as advances in renal replacement therapy have greatly improved life expectancy. Noting HPG axis abnormalities in Lowe syndrome in infancy can identify cases requiring increased surveillance of pubertal progress for earlier detection and management.

Learning points:

  • Clinical endocrine problems in Lowe syndrome has been reported, but has focused on abnormalities in adolescence and young adulthood: pubertal delay and infertility.
  • We present an infant with isolated LH elevation at baseline and on GnRH stimulation testing who also had bilateral impalpable testes.
  • Early testing of the HPG axis in patients with Lowe syndrome may help predict gonadal abnormalities from a younger age, which will enhance the overall case management into adolescence.
Open access

S A A van den Berg, N E van ‘t Veer, J M A Emmen and R H T van Beek

Summary

We present a case of iatrogenic Cushing’s syndrome, induced by treatment with fluticasone furoate (1–2 dd, 27.5 µg in each nostril) in a pediatric patient treated for congenital HIV. The pediatric patient described in this case report is a young girl of African descent, treated for congenital HIV with a combination therapy of Lopinavir/Ritonavir (1 dd 320/80 mg), Lamivudine (1 dd 160 mg) and Abacavir (1 dd 320 mg). Our pediatric patient presented with typical Cushingoid features (i.e. striae of the upper legs, full moon face, increased body and facial hair) within weeks after starting fluticasone furoate therapy, which was exacerbated after increasing the dose to 2 dd because of complaints of unresolved rhinitis. Biochemical analysis fitted iatrogenic Cushing’s syndrome, with a repeatedly low cortisol (<0.03 µM, ref 0.14–0.60 µM) and low ACTH (9 pg/mL, ref 9–52 pg/mL) without signs of adrenal insufficiency. No other biochemical abnormalities that could point to adrenal or pituitary dysfunction were detected; electrolytes, thyroid and gonadal function, and IGF-1 were within the normal range. Pharmacogenetic analysis revealed that the pediatric patient carried the CYP3A4 *1B/*1G and CYP3A5 *3/*3 genotype (associated with a partial and complete loss of enzyme activity, respectively) which is associated with the development of iatrogenic Cushing’s syndrome in patients treated for HIV due to the strong inhibition of CYP3 enzymes by Ritonavir. Upon discontinuation of fluticasone treatment, the pediatric patient improved both clinically and biochemically with normalisation of cortisol and ACTH within a couple of weeks.

Learning points:

  • Fluticasone therapy may induce iatrogenic Cushing’s syndrome in a patient treated with anti-retroviral therapy.
  • Pharmacogenetic analysis, in particular CYP3A genotyping, provides useful information in patients treated for HIV with respect to possible future steroid treatment.
  • Fluticasone furoate is not detected in the Siemens Immulite cortisol binding assay.
Open access

A Deeb, O Afandi, S Attia and A El Fatih

Summary

3-M syndrome is a rare autosomal recessive disorder caused by mutations in the CUL7, OBSL1 and CCDC8 genes. It is characterised by growth failure, dysmorphic features and skeletal abnormalities. Data in the literature show variable efficacy of GH in the treatment of short stature. We report four Emirati siblings with the condition. The index case is a 10-year-old boy with characteristic features, including prenatal and postnatal growth failure, a triangular face, a long philtrum, full lips and prominent heels. Genetic testing confirmed a novel mutation (p.val88Ala) in the CUL7 gene. The parents are healthy, first-degree cousins with nine children, of whom two died in the first year of life with respiratory failure. Both had low birth weight and growth retardation. The boy's older sibling reached an adult height of 117 cm (−6.71 SDS). She was never treated with GH. He was started on GH treatment at 7 years of age, when his height was 94 cm (−5.3 SDS). 3-M syndrome should be considered in children with short stature who have associated dysmorphism and skeletal abnormalities. The diagnosis is more likely to occur in families that have a history of consanguinity and more than one affected sibling. Death in early infancy due to respiratory failure is another clue to the diagnosis, which might have a variable phenotype within a family. Genetic testing is important for confirming the diagnosis and for genetic counselling. GH treatment might be beneficial in improving stature in affected children.

Learning points

  • 3-M syndrome should be considered in families that have more than one sibling with short stature, particularly if there is consanguinity.
  • Syndrome phenotype might be variable within a family with the same mutation.
  • Genetic analysis is helpful in confirming diagnosis in the presence of variable siblings' phenotype.
  • GH treatment might be useful in improving stature in 3-M syndrome.

Open access

Hanna Remde, Elke Kaminsky, Mathias Werner and Marcus Quinkler

Summary

We report of a male patient aged 32 years who presented with primary hyperparathyroidism. Three parathyroid glands were resected. At the age of 46 years, nervus facialis irritation was noted, and an MRI scan incidentally revealed a non-functioning pituitary adenoma with affection of the chiasma opticum. The patient underwent transsphenoidal operation resulting in pituitary insufficiency postoperatively. At the same time, primary hyperparathyroidism reoccurred and a parathyroid adenoma located at the thymus was resected. The mother of the patient died early due to multiple tumors. The patient was suspected to have multiple endocrine neoplasia type 1 (MEN1) and genetic analysis was performed. In addition, on clinical examination, multiple exostoses were noticed and an additional genetic analysis was performed. His father was reported to have multiple osteochondromas too. MEN1 was diagnosed in the patient showing a novel heterozygote mutation c.2T>A in exon 2, codon 1 (start codon ATG>AAG;p.Met1?) of the MEN1 gene. In genetic mutational analysis of the EXT1 gene, another not yet known mutation c.1418-2A>C was found in intron 5 of the EXT1 gene (heterozygotic). In conclusion, we report novel mutations of the EXT1 and the MEN1 genes causing hereditary multiple osteochondromas and MEN1 in one patient.

Learning points

  • It is important to ask for the patient's family history in detail.
  • Patients with MEN1 are characterized by the occurrence of tumors in multiple endocrine tissues and nonendocrine tissues, most frequently parathyroid (95%), enteropancreatic neuroendocrine (50%), and anterior pituitary (40%) tissues.
  • Familiar MEN1 has a high degree of penetrance (80–95%) by the age over 50; however, combinations of the tumors may be different in members of the same family.
  • Patients with EXT1 gene mutations should be monitored for possible transformation of bone lesions into osteochondrosarcoma.

Open access

Shweta Birla, Sameer Aggarwal, Arundhati Sharma and Nikhil Tandon

Summary

Carney complex (CNC) is a rare autosomal dominant syndrome characterized by pigmented lesions of the skin and mucosae along with cardiac, endocrine, cutaneous, and neural myxomatous tumors. Mutations in the PRKAR1A gene have been identified in ∼70% of the CNC cases reported worldwide. A 30-year-old male was referred to the endocrinology clinic with suspected acromegaly. He had a history of recurrent atrial myxoma for the past 8 years for which he underwent repeated surgeries. Presently, he complained of having headache, excessive snoring, sweating, and also noticed increase in his shoe size. Evaluation for acromegaly revealed elevated levels of GH in random as well as in suppressed condition. Magnetic resonance imaging scan revealed enlarged sella with microadenoma in the left anterior pituitary. Screening of PRKAR1A gene was carried out for the patient, his parents and siblings who were available and willing to undergo the test. The patient was diagnosed to have the rare CNC syndrome characterized by recurrent atrial myxoma and acromegaly due to a novel 22 bp insertion mutation in PRKAR1A which was predicted to be deleterious by in silico analysis. Screening the available family members revealed the absence of this mutation in them except the elder brother who also tested positive for this mutation. The present study reports on a novel PRKAR1A insertion mutation in a patient with acromegaly and left atrial myxoma in CNC.

Learning points

  • Identification of a novel deleterious PRKAR1A insertion mutation causing CNC.
  • It is important that patients with cardiac myxoma be investigated for presence of endocrine overactivity suggestive of CNC.
  • PRKAR1A mutation analysis should be undertaken in such cases to confirm the diagnosis in the patients as well as first degree relatives.
  • This case highlights an important aspect of diagnosis, clinical course, and management of this rare condition.

Open access

Roberto Salvatori, Adrian F Daly, Alfredo Quinones-Hinojosa, Albert Thiry and Albert Beckers

Summary

Heterozygous germline inactivating mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene lead to pituitary adenomas that most frequently present in the setting of familial isolated pituitary adenoma syndrome, usually as somatotropinomas and prolactinomas. More recently, they have been found in a significant percentage of young patients presenting with pituitary macroadenoma without any apparent family history. We describe the case of a 19-year-old man who presented with a gigantic somatotropinoma. His family history was negative. His peripheral DNA showed a heterozygous AIP mutation (p.I13N), while tumor tissue only had the mutated allele, showing loss of heterozygosity (LOH) and suggesting that the mutation caused the disease.

Learning points

  • AIP mutations may be observed in sporadic somatotrope adenomas occurring in young patients.
  • LOH is a strong indicator that an AIP variant is disease causing.
  • Somatotrope adenomas in carriers of AIP mutations are generally larger and more difficult to cure.

Open access

Ramesh Srinivasan, Stephen Ball, Martin Ward-Platt, David Bourn, Ciaron McAnulty and Tim Cheetham

Summary

Aim: Differentiating familial cranial diabetes insipidus (CDI) from primary polydipsia can be difficult. We report the diagnostic utility of genetic testing as a means of confirming or excluding this diagnosis.

Patient and methods: The index case presented at 3 months with polydipsia. He was diagnosed with familial CDI based on a positive family history combined with what was considered to be suspicious symptomatology and biochemistry. He was treated with desmopressin (DDAVP) but re-presented at 5 months of age with hyponatraemia and the DDAVP was stopped. Gene sequencing of the vasopressin gene in father and his offspring was undertaken to establish the underlying molecular defect.

Results: Both father and daughter were found to have the pathogenic mutation c.242T>C (p.Leu81Pro) in exon 2 of the AVP gene consistent with a diagnosis of familial diabetes insipidus. The index case did not have the pathogenic mutation and the family could be reassured that he would not require intervention with DDAVP.

Conclusions: Gene sequencing of AVP gene can have a valuable role in predicting whether or not a child is at risk of developing CDI in future. This can help to prevent family uncertainty and unnecessary treatment with its associated risks.

Learning points

  • Differentiating patients with familial cranial diabetes insipidus from those with primary polydipsia is not always straightforward.
  • Molecular genetic analysis of the vasopressin gene is a valuable way of confirming or refuting a diagnosis of familial CDI in difficult cases and is a valuable way of identifying individuals who will develop CDI in later childhood. This information can be of great value to families.