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Open access

Saurabh Uppal, James Blackburn, Mohammed Didi, Rajeev Shukla, James Hayden and Senthil Senniappan

Summary

Beckwith–Wiedemann syndrome (BWS) can be associated with embryonal tumours and congenital hyperinsulinism (CHI). We present an infant with BWS who developed congenital hepatoblastoma and Wilms’ tumour during infancy. The infant presented with recurrent hypoglycaemia requiring high intravenous glucose infusion and was biochemically confirmed to have CHI. He was resistant to diazoxide but responded well to octreotide and was switched to Lanreotide at 1 year of age. Genetic analysis for mutations of ABCC8 and KCNJ11 were negative. He had clinical features suggestive of BWS. Methylation-sensitive multiplex ligation-dependent probe amplification revealed hypomethylation at KCNQ1OT1:TSS-DMR and hypermethylation at H19 /IGF2:IG-DMR consistent with mosaic UPD(11p15). Hepatoblastoma was detected on day 4 of life, which was resistant to chemotherapy, requiring surgical resection. He developed Wilms’ tumour at 3 months of age, which also showed poor response to induction chemotherapy with vincristine and actinomycin D. Surgical resection of Wilms’ tumour was followed by post-operative chemotherapy intensified with cycles containing cyclophosphamide, doxorubicin, carboplatin and etoposide, in addition to receiving flank radiotherapy. We report, for the first time, an uncommon association of hepatoblastoma and Wilms’ tumour in BWS in early infancy. Early onset tumours may show resistance to chemotherapy. UPD(11p15) is likely associated with persistent CHI in BWS.

Learning points:

  • Long-acting somatostatin analogues are effective in managing persistent CHI in BWS.

  • UPD(11)pat genotype may be a pointer to persistent and severe CHI.

  • Hepatoblastoma and Wilms’ tumour may have an onset within early infancy and early tumour surveillance is essential.

  • Tumours associated with earlier onset may be resistant to recognised first-line chemotherapy.

Open access

Sarah Kiff, Carolyn Babb, Maria Guemes, Antonia Dastamani, Clare Gilbert, Sarah E Flanagan, Sian Ellard, John Barton, M Dattani and Pratik Shah

Summary

We report a case of partial diazoxide responsiveness in a child with severe congenital hyperinsulinaemic hypoglycaemia (CHI) due to a homozygous ABCC8 mutation. A term baby, with birth weight 3.8 kg, born to consanguineous parents presented on day 1 of life with hypoglycaemia. Hypoglycaemia screen confirmed CHI. Diazoxide was commenced on day 7 due to ongoing elevated glucose requirements (15 mg/kg/min), but despite escalation to a maximum dose (15 mg/kg/day), intravenous (i.v.) glucose requirement remained high (13 mg/kg/min). Genetic testing demonstrated a homozygous ABCC8 splicing mutation (c.2041-1G>C), consistent with a diffuse form of CHI. Diazoxide treatment was therefore stopped and subcutaneous (s.c.) octreotide infusion commenced. Despite this, s.c. glucagon and i.v. glucose were required to prevent hypoglycaemia. A trial of sirolimus and near-total pancreatectomy were considered, however due to the significant morbidity potentially associated with these, a further trial of diazoxide was commenced at 1.5 months of age. At a dose of 10 mg/kg/day of diazoxide and 40 µg/kg/day of octreotide, both i.v. glucose and s.c. glucagon were stopped as normoglycaemia was achieved. CHI due to homozygous ABCC8 mutation poses management difficulties if the somatostatin analogue octreotide is insufficient to prevent hypoglycaemia. Diazoxide unresponsiveness is often thought to be a hallmark of recessively inherited ABCC8 mutations. This patient was initially thought to be non-responsive, but this case highlights that a further trial of diazoxide is warranted, where other available treatments are associated with significant risk of morbidity.

Learning points:

  • Homozygous ABCC8 mutations are commonly thought to cause diazoxide non-responsive hyperinsulinaemic hypoglycaemia.

  • This case highlights that partial diazoxide responsiveness in homozygous ABCC8 mutations may be present.

  • Trial of diazoxide treatment in combination with octreotide is warranted prior to considering alternative treatments, such as sirolimus or near-total pancreatectomy, which are associated with more significant side effects.

Open access

Dinesh Giri, Prashant Patil, Rachel Hart, Mohammed Didi and Senthil Senniappan

Summary

Poland syndrome (PS) is a rare congenital condition, affecting 1 in 30 000 live births worldwide, characterised by a unilateral absence of the sternal head of the pectoralis major and ipsilateral symbrachydactyly occasionally associated with abnormalities of musculoskeletal structures. A baby girl, born at 40 weeks’ gestation with birth weight of 3.33 kg (−0.55 SDS) had typical phenotypical features of PS. She had recurrent hypoglycaemic episodes early in life requiring high concentration of glucose and glucagon infusion. The diagnosis of congenital hyperinsulinism (CHI) was biochemically confirmed by inappropriately high plasma concentrations of insulin and C-peptide and low plasma free fatty acids and β-hydroxyl butyrate concentrations during hypoglycaemia. Sequencing of ABCC8, KCNJ11 and HNF4A did not show any pathogenic mutation. Microarray analysis revealed a novel duplication in the short arm of chromosome 10 at 10p13–14 region. This is the first reported case of CHI in association with PS and 10p duplication. We hypothesise that the HK1 located on the chromosome 10 encoding hexokinase-1 is possibly linked to the pathophysiology of CHI.

Learning points:

  • Congenital hyperinsulinism (CHI) is known to be associated with various syndromes.

  • This is the first reported association of CHI and Poland syndrome (PS) with duplication in 10p13–14.

  • A potential underlying genetic link between 10p13–14 duplication, PS and CHI is a possibility.

Open access

Suresh Chandran, Fabian Yap Kok Peng, Victor Samuel Rajadurai, Yap Te Lu, Kenneth T E Chang, S E Flanagan, S Ellard and Khalid Hussain

Summary

background: Congenital hyperinsulinism (CHI) is a rare genetic disorder characterised by inappropriate insulin secretion in the face of severe hypoglycaemia. There are two histological subtypes of CHI namely diffuse and focal. Diffuse CHI is most common due to recessive mutations in ABCC8/KCNJ11 (which encode the SUR/KIR6.2 components of the pancreatic β-cell KATP channel) whereas focal CHI is due to a paternally inherited ABCC8/KCNJ11 mutation and somatic loss of heterozygosity for the 11p allele inside the focal lesion. Fluorine-18-l-dihydroxyphenylalanine positron emission tomography/computed tomography (18F-DOPA-PET/CT) is used in the pre-operative localisation of focal lesions prior to surgery. Diffuse CHI if medically unresponsive will require a near total pancreatectomy whereas focal CHI will only require a limited lesionectomy, thus curing the patient from the hypoglycaemia.

Aims: To report the first case of genetically confirmed CHI in Singapore from a heterozygous paternally inherited ABCC8 mutation.

Methods/Results: A term male infant presented with severe hyperinsulinaemic hypoglycaemia (HH) after birth and failed medical treatment with diazoxide and octreotide. Genetic testing (paternally inherited mutation in ABCC8/p.D1472N) suggested focal disease, but due to the unavailability of 18F-DOPA-PET/CT to confirm focal disease, a partial pancreatectomy was performed. Interestingly, histology of the resected pancreatic tissue showed changes typical of diffuse disease.

Conclusion: Heterozygous paternally inherited ABCC8/KCNJ11 mutations can lead to diffuse or focal CHI.

Learning points

  • HH is a cause of severe hypoglycaemia in the newborn period.

  • Paternal mutations in ABCC8/KCNJ11 can lead to diffuse or focal disease.

  • 18F-DOPA-PET/CT scan is the current imaging of choice for localising focal lesions.

  • Gallium-68 tetra-aza-cyclododecane-N NNN-‴-tetra-acetate octreotate PET scan is not a useful imaging tool for localising focal lesions.

  • The molecular mechanism by which a heterozygous ABCC8 mutation leads to diffuse disease is currently unclear.

  • Focal lesions are curable by lesionectomy and so genetic studies in patients with HH must be followed by imaging using 18F-DOPA-PET/CT scan.