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Open access

Thien Vinh Luong, Lars Rejnmark, Anne Kirstine Arveschoug, Peter Iversen and Lars Rolighed

Multiple endocrine neoplasia 1 (MEN1) is a rare genetic syndrome characterized by the manifestation of tumors in endocrine glands most often in the parathyroid gland (PG). Treatment may involve several parathyroidectomies (PTX), especially in young patients, which increases the risk of postoperative complications. We present a 16-year-old patient with a family history of MEN1 syndrome. The patient started to show biochemical signs of hyperparathyroidism (HPT) and hypercalcemia at the age of 10. One and a half years later a PTX was successfully performed with removal of the two left PGs. However, a rise in plasma parathyroid hormone and ionized calcium was observed 4 years later. Preoperative noninvasive imaging with 99mTc-sestamibi scintigraphy showed no definitive parathyroid adenoma. A 11C-methionine position emission tomography combined with MRI (MET-PET/MRI) was then performed and detected a focus posterior to the lower part of the right thyroid lobe. Intraoperative angiography with fluorescence and indocyanine green dye was used to assess the vascularization of the remaining PGs. The lower right PG was removed. The patient was discharged with normalized biochemical values and without postoperative complications. Recurrence of primary HPT is frequent in MEN1 patients which often necessitates repeated operations. Our case report showed that the use of advanced noninvasive preoperative imaging techniques and intraoperative fluorescent imaging are valuable tools and should be taken into consideration in selected cases to avoid postoperative complications. To our knowledge, this is the first case where MET-PET/MRI has been used to detect parathyroid pathology.

Learning points:

  • MEN1 patients will develop parathyroid disease, which eventually will lead to surgical treatment with removal of the pathological glands.
  • Preoperatively usage of MRI combined with PET tracers such as 11C-methionine and 18F-Fluorocholine are able to detect parathyroid pathology with a higher sensitivity than conventional imaging.
  • Techniques using intraoperatively angiography with fluorescence and florescent dyes allow surgeons to verify the vascularization of each parathyroid gland.
  • Optimization of noninvasive preoperative imaging techniques and intraoperative fluorescent imaging are valuable tools and should be taken into consideration when performing PTX consecutively in the same patient to avoid postoperative complications.
Open access

Sarah W Y Poon, Karen K Y Leung and Joanna Y L Tung

Summary

Severe hypertriglyceridemia is an endocrine emergency and is associated with acute pancreatitis and hyperviscosity syndrome. We describe an infant with lipoprotein lipase deficiency with severe hypertriglyceridemia who presented with acute pancreatitis. She was managed acutely with fasting and intravenous insulin infusion, followed by low-fat diet with no pharmacological agent. Subsequent follow-up until the age of 5 years showed satisfactory lipid profile and she has normal growth and development.

Learning points:

  • Hypertriglyceridemia-induced acute pancreatitis has significant morbidity and mortality, and prompt treatment is imperative.
  • When no secondary causes are readily identified, genetic evaluation should be pursued in hypertriglyceridemia in children.
  • Intravenous insulin is a safe and effective acute treatment for hypertriglyceridemia in children, even in infants.
  • Long-term management with dietary modifications alone could be effective for primary hypertriglyceridemia due to lipoprotein lipase deficiency, at least in early childhood phase.
Open access

Daphne Yau, Maria Salomon-Estebanez, Amish Chinoy, John Grainger, Ross J Craigie, Raja Padidela, Mars Skae, Mark J Dunne, Philip G Murray and Indraneel Banerjee

Summary

Congenital hyperinsulinism (CHI) is an important cause of severe hypoglycaemia in infancy. To correct hypoglycaemia, high concentrations of dextrose are often required through a central venous catheter (CVC) with consequent risk of thrombosis. We describe a series of six cases of CHI due to varying aetiologies from our centre requiring CVC for the management of hypoglycaemia, who developed thrombosis in association with CVC. We subsequently analysed the incidence and risk factors for CVC-associated thrombosis, as well as the outcomes of enoxaparin prophylaxis. The six cases occurred over a 3-year period; we identified an additional 27 patients with CHI who required CVC insertion during this period (n = 33 total), and a separate cohort of patients with CHI and CVC who received enoxaparin prophylaxis (n = 7). The incidence of CVC-associated thrombosis was 18% (6/33) over the 3 years, a rate of 4.2 thromboses/1000 CVC days. There was no difference in the frequency of genetic mutations or focal CHI in those that developed thromboses. However, compound heterozygous/homozygous potassium ATP channel mutations correlated with thrombosis (R 2 = 0.40, P = 0.001). No difference was observed in CVC duration, high concentration dextrose or glucagon infused through the CVC. In patients receiving enoxaparin prophylaxis, none developed thrombosis or bleeding complications. The characteristics of these patients did not differ significantly from those with thrombosis not on prophylaxis. We therefore conclude that CVC-associated thrombosis can occur in a significant proportion (18%) of patients with CHI, particularly in severe CHI, for which anticoagulant prophylaxis may be indicated.

Learning points:

  • CVC insertion is one of the most significant risk factors for thrombosis in the paediatric population.
  • Risk factors for CVC-associated thrombosis include increased duration of CVC placement, malpositioning and infusion of blood products.
  • To our knowledge, this is the first study to evaluate CVC-associated thrombosis in patients with congenital hyperinsulinism (CHI).
  • The incidence of CVC-associated thrombosis development is significant (18%) in CHI patients and higher compared to other neonates with CVC. CHI severity may be a risk factor for thrombosis development.
  • Although effective prophylaxis for CVC-associated thrombosis in infancy is yet to be established, our preliminary experience suggests the safety and efficacy of enoxoaparin prophylaxis in this population and requires on-going evaluation.
Open access

A Chinoy, N B Wright, M Bone and R Padidela

Summary

Hypokalaemia at presentation of diabetic ketoacidosis is uncommon as insulin deficiency and metabolic acidosis shifts potassium extracellularly. However, hypokalaemia is a recognised complication of the management of diabetic ketoacidosis as insulin administration and correction of metabolic acidosis shifts potassium intracellularly. We describe the case of a 9-year-old girl with newly diagnosed type 1 diabetes mellitus presenting in diabetic ketoacidosis, with severe hypokalaemia at presentation due to severe and prolonged emesis. After commencing management for her diabetic ketoacidosis, her serum sodium and osmolality increased rapidly. However, despite maximal potassium concentrations running through peripheral access, and multiple intravenous potassium ‘corrections’, her hypokalaemia persisted. Seventy two hours after presentation, she became drowsy and confused, with imaging demonstrating central pontine myelinolysis – a rare entity seldom seen in diabetic ketoacidosis management in children despite rapid shifts in serum sodium and osmolality. We review the literature associating central pontine myelinolysis with hypokalaemia and hypothesise as to how the hypokalaemia may have contributed to the development of central pontine myelinolysis. We also recommend an approach to the management of a child in diabetic ketoacidosis with hypokalaemia at presentation.

Learning points:

  • Hypokalaemia is a recognised complication of treatment of paediatric diabetic ketoacidosis that should be aggressively managed to prevent acute complications.
  • Central pontine myelinolysis is rare in children, and usually observed in the presence of rapid correction of hyponatraemia. However, there is observational evidence of an association between hypokalaemia and central pontine myelinolysis, potentially by priming the endothelial cell membrane to injury by lesser fluctuations in osmotic pressure.
  • Consider central pontine myelinolysis as a complication of the management of paediatric diabetic ketoacidosis in the presence of relevant symptoms with profound hypokalaemia and/or fluctuations in serum sodium levels.
  • We have suggested an approach to the management strategies of hypokalaemia in paediatric diabetic ketoacidosis which includes oral potassium supplements if tolerated, minimising the duration and the rate of insulin infusion and increasing the concentration of potassium intravenously (via central line if necessary).
Open access

Ved Bhushan Arya, Jennifer Kalitsi, Ann Hickey, Sarah E Flanagan and Ritika R Kapoor

Summary

Diazoxide is the first-line treatment for patients with hyperinsulinaemic hypoglycaemia (HH). Approximately 50% of patients with HH are diazoxide resistant. However, marked diazoxide sensitivity resulting in severe hyperglycaemia is extremely uncommon and not reported previously in the context of HH due to HNF4A mutation. We report a novel observation of exceptional diazoxide sensitivity in a patient with HH due to HNF4A mutation. A female infant presented with severe persistent neonatal hypoglycaemia and was diagnosed with HH. Standard doses of diazoxide (5 mg/kg/day) resulted in marked hyperglycaemia (maximum blood glucose 21.6 mmol/L) necessitating discontinuation of diazoxide. Lower dose of diazoxide (1.5 mg/kg/day) successfully controlled HH in the proband, which was subsequently confirmed to be due to a novel HNF4A mutation. At 3 years of age, the patient maintains age appropriate fasting tolerance on low dose diazoxide (1.8 mg/kg/day) and has normal development. Diagnosis in proband’s mother and maternal aunt, both of whom carried HNF4A mutation and had been diagnosed with presumed type 1 and type 2 diabetes mellitus, respectively, was revised to maturity-onset diabetes of young (MODY). Proband’s 5-year-old maternal cousin, also carrier of HNF4A mutation, had transient neonatal hypoglycaemia. To conclude, patients with HH due to HNF4A mutation may require lower diazoxide than other group of patients with HH. Educating the families about the risk of marked hyperglycaemia with diazoxide is essential. The clinical phenotype of HNF4A mutation can be extremely variable.

Learning points:

  • Awareness of risk of severe hyperglycaemia with diazoxide is important and patients/families should be accordingly educated.
  • Some patients with HH due to HNF4A mutations may require lower than standard doses of diazoxide.
  • The clinical phenotype of HNF4A mutation can be extremely variable.
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

Susan Ahern, Mark Daniels and Amrit Bhangoo

Summary

In this case report, we present a novel mutation in Lim-homeodomain (LIM-HD) transcription factor, LHX3, manifesting as combined pituitary hormone deficiency (CPHD). This female patient was originally diagnosed in Egypt during infancy with Diamond Blackfan Anemia (DBA) requiring several blood transfusions. Around 10 months of age, she was diagnosed and treated for central hypothyroidism. It was not until she came to the United States around two-and-a-half years of age that she was diagnosed and treated for growth hormone deficiency. Her response to growth hormone replacement on linear growth and muscle tone were impressive. She still suffers from severe global development delay likely due to delay in treatment of congenital central hypothyroidism followed by poor access to reliable thyroid medications. Her diagnosis of DBA was not confirmed after genetic testing in the United States and her hemoglobin normalized with hormone replacement therapies. We will review the patient’s clinical course as well as a review of LHX3 mutations and the associated phenotype.

Learning points:

  • Describe an unusual presentation of undertreated pituitary hormone deficiencies in early life
  • Combined pituitary hormone deficiency due to a novel mutation in pituitary transcription factor, LHX3
  • Describe the clinical phenotype of combined pituitary hormone deficiency due to LHX3 mutations
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

George Stoyle, Siddharth Banka, Claire Langley, Elizabeth A Jones and Indraneel Banerjee

Summary

Wiedemann–Steiner Syndrome (WSS) is a rare condition characterised by short stature, hypertrichosis of the elbow, intellectual disability and characteristic facial dysmorphism due to heterozygous loss of function mutations in KMT2A, a gene encoding a histone 3 lysine 4 methyltransferase. Children with WSS are often short and until recently, it had been assumed that short stature is an intrinsic part of the syndrome. GHD has recently been reported as part of the phenotypic spectrum of WSS. We describe the case of an 8-year-old boy with a novel heterozygous variant in KMT2A and features consistent with a diagnosis of WSS who also had growth hormone deficiency (GHD). GHD was diagnosed on dynamic function testing for growth hormone (GH) secretion, low insulin-like growth factor I (IGF-I) levels and pituitary-specific MRI demonstrating anterior pituitary hypoplasia and an ectopic posterior pituitary. Treatment with GH improved height performance with growth trajectory being normalised to the parental height range. Our case highlights the need for GH testing in children with WSS and short stature as treatment with GH improves growth trajectory.

Learning points:

  • Growth hormone deficiency might be part of the phenotypic spectrum of Wiedemann–Steiner Syndrome (WSS).
  • Investigation of pituitary function should be undertaken in children with WSS and short stature. A pituitary MR scan should be considered if there is biochemical evidence of growth hormone deficiency (GHD).
  • Recombinant human growth hormone treatment should be considered for treatment of GHD.