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Open access

Catherine D Zhang, Pavel N Pichurin, Aleh Bobr, Melanie L Lyden, William F Young Jr and Irina Bancos

Summary

Carney complex (CNC) is a rare multiple neoplasia syndrome characterized by spotty pigmentation of the skin and mucosa in association with various non-endocrine and endocrine tumors, including primary pigmented nodular adrenocortical disease (PPNAD). A 20-year-old woman was referred for suspected Cushing syndrome. She had signs of cortisol excess as well as skin lentigines on physical examination. Biochemical investigation was suggestive of corticotropin (ACTH)-independent Cushing syndrome. Unenhanced computed tomography scan of the abdomen did not reveal an obvious adrenal mass. She subsequently underwent bilateral laparoscopic adrenalectomy, and histopathology was consistent with PPNAD. Genetic testing revealed a novel frameshift pathogenic variant c.488delC/p.Thr163MetfsX2 (ClinVar Variation ID: 424516) in the PRKAR1A gene, consistent with clinical suspicion for CNC. Evaluation for other clinical features of the complex was unrevealing. We present a case of PPNAD-associated Cushing syndrome leading to the diagnosis of CNC due to a novel PRKAR1A pathogenic variant.

Learning points:

  • PPNAD should be considered in the differential for ACTH-independent Cushing syndrome, especially when adrenal imaging appears normal.

  • The diagnosis of PPNAD should prompt screening for CNC.

  • CNC is a rare multiple neoplasia syndrome caused by inactivating pathogenic variants in the PRKAR1A gene.

  • Timely diagnosis of CNC and careful surveillance can help prevent potentially fatal complications of the disease.

Open access

Alejandro García-Castaño, Leire Madariaga, Sharona Azriel, Gustavo Pérez de Nanclares, Idoia Martínez de LaPiscina, Rosa Martínez, Inés Urrutia, Aníbal Aguayo, Sonia Gaztambide and Luis Castaño

Summary

Familial hypocalciuric hypercalcemia type I is an autosomal dominant disorder caused by heterozygous loss-of-function mutations in the CASR gene and is characterized by moderately elevated serum calcium concentrations, low urinary calcium excretion and inappropriately normal or mildly elevated parathyroid hormone (PTH) concentrations. We performed a clinical and genetic characterization of one patient suspected of familial hypocalciuric hypercalcemia type I. Patient presented persistent hypercalcemia with normal PTH and 25-hydroxyvitamin D levels. The CASR was screened for mutations by PCR followed by direct Sanger sequencing and, in order to detect large deletions or duplications, multiplex ligation-dependent probe amplification (MLPA) was used. One large deletion of 973 nucleotides in heterozygous state (c.1733-255_2450del) was detected. This is the first large deletion detected by the MLPA technique in the CASR gene.

Learning points:

  • Molecular studies are important to confirm the differential diagnosis of FHH from primary hyperparathyroidism.

  • Large deletions or duplications in the CASR gene can be detected by the MLPA technique.

  • Understanding the functional impact of the mutations is critical for leading pharmacological research and could facilitate the therapy of patients.

Open access

Ohoud Al Mohareb, Mussa H Al Malki, O Thomas Mueller and Imad Brema

Summary

Resistance to thyroid hormone-beta (RTHbeta) is a rare inherited syndrome characterized by variable reduced tissue responsiveness to the intracellular action of triiodothyronine (T3), the active form of the thyroid hormone. The presentation of RTHbeta is quite variable and mutations in the thyroid hormone receptor beta (THR-B) gene have been detected in up to 90% of patients. The proband was a 34-year-old Jordanian male who presented with intermittent palpitations. His thyroid function tests (TFTs) showed a discordant profile with high free T4 (FT4) at 45.7 pmol/L (normal: 12–22), high free T3 (FT3) at 11.8 pmol/L (normal: 3.1–6.8) and inappropriately normal TSH at 3.19 mIU/L (normal: 0.27–4.2). Work up has confirmed normal alpha subunit of TSH of 0.1 ng/mL (normal <0.5) and pituitary MRI showed no evidence of a pituitary adenoma; however, there was an interesting coincidental finding of partially empty sella. RTHbeta was suspected and genetic testing confirmed a known mutation in the THR-B gene, where a heterozygous A to G base change substitutes valine for methionine at codon 310. Screening the immediate family revealed that the eldest son (5 years old) also has discordant thyroid function profile consistent with RTHbeta and genetic testing confirmed the same M310V mutation that his father harbored. Moreover, the 5-year-old son had hyperactivity, impulsivity and aggressive behavior consistent with attention deficit hyperactivity disorder (ADHD). This case demonstrates an unusual co-existence of RTHbeta and partially empty sella in the same patient which, to our knowledge, has not been reported before.

Learning points:

  • We report the coincidental occurrence of RTHbeta and a partially empty sella in the same patient that has not been previously reported.

  • TFTs should be done in all children who present with symptoms suggestive of ADHD as RTHbeta is a common finding in these children.

  • The management of children with ADHD and RTHbeta could be challenging for both pediatricians and parents and the administration of T3 with close monitoring may be helpful in some cases.

  • Incidental pituitary abnormalities do exist in patients with RTHbeta, although extremely rare, and should be evaluated thoroughly and separately.

Open access

M A Shehab, Tahseen Mahmood, M A Hasanat, Md Fariduddin, Nazmul Ahsan, Mohammad Shahnoor Hossain, Md Shahdat Hossain and Sharmin Jahan

Summary

Congenital adrenal hyperplasia (CAH) due to the three-beta-hydroxysteroid-dehydrogenase (3β-HSD) enzyme deficiency is a rare autosomal recessive disorder presenting with sexual precocity in a phenotypic male. Klinefelter syndrome (KS) is the most common sex chromosome aneuploidy presenting with hypergonadotropic hypogonadism in a male. However, only a handful of cases of mosaic KS have been described in the literature. The co-existence of mosaic KS with CAH due to 3β-HSD enzyme deficiency portrays a unique diagnostic paradox where features of gonadal androgen deficiency are masked by simultaneous adrenal androgen excess. Here, we report a 7-year-old phenotypic male boy who, at birth presented with ambiguous genitalia, probably a microphallus with penoscrotal hypospadias. Later on, he developed accelerated growth with advanced bone age, premature pubarche, phallic enlargement and hyperpigmentation. Biochemically, the patient was proven to have CAH due to 3β-HSD deficiency. However, the co-existence of bilateral cryptorchidism made us to consider the possibility of hypogonadism as well, and it was further explained by concurrent existence of mosaic KS (47,XXY/46,XX). He was started on glucocorticoid and mineralocorticoid replacement and underwent right-sided orchidopexy on a later date. He showed significant clinical and biochemical improvement on subsequent follow-up. However, the declining value of serum testosterone was accompanied by rising level of FSH thereby unmasking hypergonadotropic hypogonadism due to mosaic KS. In future, we are planning to place him on androgen replacement as well.

Learning points:

  • Ambiguous genitalia with subsequent development of sexual precocity in a phenotypic male points towards some unusual varieties of CAH.

  • High level of serum testosterone, adrenal androgen, plasma ACTH and low basal cortisol are proof of CAH, whereas elevated level of 17-OH pregnenolone is biochemical marker of 3β-HSD enzyme deficiency.

  • Final diagnosis can be obtained with sequencing of HSD3B2 gene showing various mutations.

  • Presence of bilateral cryptorchidism in such a patient may be due to underlying hypogonadism.

  • Karyotyping in such patient may rarely show mosaic KS (47,XXY/46,XX) and there might be unmasking of hypergonadotropic hypogonadism resulting from adrenal androgen suppression from glucocorticoid treatment.

Open access

Benjamin Kwan, Bernard Champion, Steven Boyages, Craig F Munns, Roderick Clifton-Bligh, Catherine Luxford and Bronwyn Crawford

Summary

Autosomal dominant hypocalcaemia type 1 (ADH1) is a rare familial disorder characterised by low serum calcium and low or inappropriately normal serum PTH. It is caused by activating CASR mutations, which produces a left-shift in the set point for extracellular calcium. We describe an Australian family with a novel heterozygous missense mutation in CASR causing ADH1. Mild neuromuscular symptoms (paraesthesia, carpopedal spasm) were present in most affected individuals and required treatment with calcium and calcitriol. Basal ganglia calcification was present in three out of four affected family members. This case highlights the importance of correctly identifying genetic causes of hypocalcaemia to allow for proper management and screening of family members.

Learning points:

  • ADH1 is a rare cause of hypoparathyroidism due to activating CASR mutations and is the mirror image of familial hypocalciuric hypercalcaemia.

  • In patients with ADH1, symptoms of hypocalcaemia may be mild or absent. Basal ganglia calcification may be present in over a third of patients.

  • CASR mutation analysis is required for diagnostic confirmation and to facilitate proper management, screening and genetic counselling of affected family members.

  • Treatment with calcium and activated vitamin D analogues should be reserved for symptomatic individuals due to the risk of exacerbating hypercalciuria and its associated complications.

Open access

Haruhiro Sato and Yuichiro Tomita

Summary

Resistance to thyroid hormone (RTH), which is primarily caused by mutations in the thyroid hormone (TH) receptor beta (THRB) gene, is dominantly inherited syndrome of variable tissue hyposensitivity to TH. We herein describe a case involving a 22-year-old Japanese man with RTH and atrial fibrillation (AF) complaining of palpitation and general fatigue. Electrocardiography results revealed AF. He exhibited elevated TH levels and an inappropriately normal level of thyroid-stimulating hormone (TSH). Despite being negative for anti-TSH receptor antibody, thyroid-stimulating antibody and anti-thyroperoxidase antibody, the patient was positive for anti-thyroglobulin (Tg) antibody. Genetic analysis of the THRB gene identified a missense mutation, F269L, leading to the diagnosis of RTH. Normal sinus rhythm was achieved after 1 week of oral bisoprolol fumarate (5 mg/day) administration. After 3 years on bisoprolol fumarate, the patient had been doing well with normal sinus rhythm, syndrome of inappropriate secretion of TSH (SITSH) and positive titer of anti-Tg antibody.

Learning points:

  • Atrial fibrillation can occur in patients with RTH.

  • Only a few cases have been reported on the coexistence of RTH and atrial fibrillation.

  • No consensus exists regarding the management of atrial fibrillation in patients with RTH.

  • Administration of bisoprolol fumarate, a beta-blocker, can ameliorate atrial fibrillation in RTH.

Open access

Jennifer Hague, Ruth Casey, Jonathan Bruty, Tom Legerton, Stephen Abbs, Susan Oddy, Andrew S Powlson, Mohamed Majeed, Mark Gurnell, Soo-Mi Park and Helen Simpson

Summary

Activating mutations in AVPR2 are associated with nephrogenic syndrome of inappropriate antidiuresis (NSIAD). NSIAD causes hyponatremia, decreased serum osmolality and clinical symptoms, which may present from birth or in infancy and include hypotonia, irritability, vomiting and/or seizures. Symptoms in later life are often less specific and include malaise, dizziness, confusion, tiredness and headache. NSIAD is a rare X-linked condition, which is associated with a variable phenotype in males, of whom some present in infancy but others do not become symptomatic until adulthood, or occasionally, never. Female carriers may present with episodes of hyponatremia, usually found incidentally. Literature in this field is limited; namely, two clinical reports describing a female proband, both diagnosed in infancy. We describe, for the first time, the case of an adult female proband with NSIAD, who had longstanding associated symptoms of tiredness, headache, temporary memory loss and mood changes as well as hyponatremia and decreased serum osmolality. A water load test demonstrated an inability to dilute urine and gene sequencing confirmed a recurrent activating mutation in AVPR2. The variant was inherited from the proband’s mother who had had longstanding episodes of transient asymptomatic hyponatremia. This is the third report of a female proband with NSIAD and is the first female reported who sought medical treatment for chronic symptoms from adulthood. This case acts as a reminder of the importance of considering NSIAD as a diagnosis in females of all ages with unexplained hyponatremia.

Learning points:

  • Activating mutations in the AVPR2 gene are associated with the rare X-linked condition nephrogenic syndrome of inappropriate antidiuresis.

  • NSIAD is associated with hyponatremia, decreased serum osmolality and inappropriately increased urinary osmolality. Early clinical symptoms in infancy include hypotonia, irritability, vomiting and/or seizures. Symptoms in later life include malaise, dizziness, confusion, tiredness and headache.

  • NSIAD should be considered in female, as well as male, patients who present with unexplained hyponatremia and decreased serum osmolality. Family history may reveal relevant symptoms or biochemical features in other family members. However, family history may not always be informative due to the variable nature of the condition or if the proband has a de novo pathogenic variant.

  • A water load test with measurement of AVP may be informative in distinguishing NSIAD from SIADH. Measurement of co-peptin levels may be considered, in substitution for direct measurement of AVP.

  • Patients with NSIAD should be counseled about appropriate daily fluid volume intake. Potential episodes of fluid overload should be avoided.

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

I Castilla-Cortazar, J R De Ita, G A Aguirre, M García–Magariño, I Martín-Estal, V J Lara-Diaz and M I Elizondo

Summary

Herein, we present a 14-year-old patient with short stature (134 cm) referred from Paediatrics to our department for complementary evaluation since growth hormone (GH) treatment failed to show any improvement. He was born premature and small for gestational age. Genital examination classified the patient as Tanner I–II with small penis and testicular size for his age. Biochemical analyses revealed normal GH levels with low serum insulin-like growth factor-1 (IGF-1). Molecular diagnosis confirmed several mutations in IGF1R and IGFALS, and so he was diagnosed with Laron Syndrome or GH insensibility and treated with IGF-1 substitutive therapy.

Learning points:

  • Evaluation of the GH/IGF-1 axis when short stature does not respond to conservative treatment must be included in the ordinary practice.

  • Laron Syndrome real incidence should be calculated once undiagnosed cases arise, as treatment, due to lack of market, is unaffordable.

  • Even when adulthood is reached, and no longitudinal growth can be achieved, still IGF-1 treatment in Laron Syndrome patients should be pursued as metabolic and protective derangements could arise.

Open access

Judith Gerards, Michael M Ritter, Elke Kaminsky, Andreas Gal, Wolfgang Hoeppner and Marcus Quinkler

Summary

DAX1 (NR0B1) is an orphan nuclear receptor, which plays an important role in development and function of the adrenal glands and gonads. Mutations in DAX1 cause X-linked adrenal hypoplasia congenita (X-linked AHC), which is characterized by adrenal insufficiency (AI) and hypogonadotropic hypogonadism (HHG). Affected boys present with adrenal failure usually in childhood and, later in life, with delayed puberty. However, patients with a late-onset form of X-linked AHC have also been described in the past years. We report a male patient who presented with symptoms of an adrenal crisis at the age of 38 years and was later diagnosed with HHG. Family history was positive with several male relatives diagnosed with AI and compatible with the assumed X-chromosomal inheritance of the trait. Direct sequencing of DAX1 of the patient revealed a hemizygous cytosine-to-thymine substitution at nucleotide 64 in exon 1, which creates a novel nonsense mutation (p.(Gln22*)). In order to compare the clinical presentation of the patient to that of other patients with X-linked AHC, we searched the electronic database MEDLINE (PubMed) and found reports of nine other cases with delayed onset of X-linked AHC. In certain cases, genotype–phenotype correlation could be assumed.

Learning points:

  • X-linked AHC is a rare disease characterized by primary AI and hypogonadotropic hypogonadism (HHG). The full-blown clinical picture is seen usually only in males with a typical onset in childhood.

  • Patients with a late-onset form of X-linked AHC have also been described recently. Being aware of this late-onset form might help to reach an early diagnosis and prevent life-threatening adrenal crises.

  • Adult men with primary AI of unknown etiology should be investigated for HHG. Detecting a DAX1 mutation may confirm the clinical diagnosis of late-onset X-linked AHC.

  • In relatives of patients with genetically confirmed X-linked AHC, targeted mutation analysis may help to identify family members at risk and asymptomatic carriers, and discuss conscious family planning.