Search tips
Search criteria 


Logo of annsaudimedHomeCurrent issueInstructionsSubmit article
Ann Saudi Med. 2010 Mar-Apr; 30(2): 162–164.
PMCID: PMC2855071

Successful transfer from insulin to oral sulfonylurea in a 3-year-old girl with a mutation in the KCNJ11 gene


Neonatal diabetes mellitus is considered a rare disease that is diagnosed in the first six months of life, and can be either transient or permanent. Recent advances in molecular genetics have shown that activating mutations in KCNJ11 (the gene that encodes for the Kir6.2 subunit of the KATP potassium channel of the pancreatic β-cell) is a common cause of permanent neonatal diabetes mellitus. Patients with mutations in this gene may respond to oral sulfonyureas. We describe a 3-year-old girl with permanent neonatal diabetes mellitus with a mutation in the KCNJ11 gene (R201H), who was successfully transferred from subcutaneous insulin to oral glibenclamide, with a marked improvement in glycemic control. This is the first successful switch from insulin to oral sulfonylurea in a patient with R201H mutation, in the Arabian Gulf.

Neonatal diabetes mellitus (NDM) is a rare disease with an incidence of 1 in 500 000 newborns. Neonates present with intrauterine growth retardation (IUGR) due to intrauterine insulin deficiency, glucosuria, polyuria, failure to thrive, and ketoacidosis, which usually appear in the first six months of life. Administration of insulin results in a dramatic improvement in the symptoms and growth.1 NDM can present as permanent neonatal diabetes (PNDM) or transient neonatal diabetes mellitus (TNDM) that can sometimes be differentiated clinically. Molecular genetic analysis can dramatically differentiate between the two subtypes from the onset of the disease.2 The common causes of PNDM are activating mutations in the KCNJ11 gene, which encodes the Kir6.2 subunit of the KATP sensitive channel of the pancreatic β-cell.2 Mutations in KCNJ11 cause PNDM in about 53% of the cases.3 We report a case with a de novo heterozygous mutation in the KCNJ11 (R201 H) gene that was successfully transformed from subcutaneous insulin to oral sulfonylurea. This mutation results in the inability of the KATP channel to close, in the presence of increased sensitivity of potassium channel (ATP). It has previously been observed that the introduction of sulfonyurea can close these channels by an ATP-independent mechanism.4


Our patient was 3 years old when she was diagnosed as having a de novo heterozygous mutation in the KCNJ11 gene and transfered from subcutaneous insulin to oral glibenclamide. She was born at 40-weeks gestation, with a birth weight of 2 kg, to a healthy mother with no history of gestational diabetes. Her parents were consanguineous with no history of diabetes in the first- or second-degree relatives. At the age of 50 days she was admitted with an acute illness in the form of fever, vomiting, and diarrhea and she was found to have hyperglycemia (blood glucose >20 mmol/L) with no clinical or biochemical evidence of ketoacidosis. As her hyperglycemia was persistent she was started on subcutaneous insulin isophane NPH twice daily (0.3-0.5 units/kg/day). Her initial glycated hemoglobin (HbA1c) was 9% (reference range 4.4-6.4%). Ultrasound of the abdomen showed the presence of pancreatic tissue. A skeletal survey was normal and liver function was normal. She was transferred to us for tertiary care at the age of two years where DNA molecular analysis was done for both parents and patient, after obtaining formal consent. At that time she was clinically well with normal development, and normal physical and neurological assessment. Her HbA1c then was 12% so she was changed to subcutaneous insulin glargine and rapid-acting analogs for better control. Her capillary blood glucose was measured four to six times per day (range of 15-20 mmol/L) with normal diet for her age. There was mild improvement in her HbA1c to 10-11% on changing her insulin regimen.

Genomic DNA was extracted from the peripheral leukocytes using standard procedures and the single exon of the KCNJ11 gene was sequenced as previously described.5 Sequencing of the KCNJ11 gene detected a de novo heterozygous mutation in the KCNJ11 gene (R201H) (Figure 1). At the age of three years the molecular genetic analysis showed that our patient had a de novo heterozygous mutation in the KCNJ11 gene (R201H). The parents were informed and the child was admitted as an in-patient for transfer to oral sulfonylurea glibenclamide. The patient was transferred for a rapid in-patient transfer protocol.3 Before starting glibenclamide, the physical examination and neurological assessment were performed, and they were normal for age. Regular capillary blood glucose monitoring was done four to six times a day, the blood was tested for ketones, the HbA1c was checked, and the usual daily dose of insulin was given prior to transfer. On the day glibenclamide was started, an oral glucose tolerance test was performed by giving glucose orally in a dose of 1.75 g/kg. After a sample of fasting blood glucose, insulin level, C peptide was obtained, followed by a postprandial glucose sample. After the oral glucose tolerance test (OGTT) a meal was allowed with rapid acting insulin and the first dose of glibenclamide was given, 0.1 mg/kg/dose, twice daily, in the form of a 5 mg tablet dissolved in water, at a concentration of 5 mg/ml. The following day's long-acting insulin was omitted; rapid acting insulin was continued as necessary, increasing glibenclamide by 0.2 mg/kg/day and continuing capillary blood glucose monitoring. She reached a dose of 0.8 mg/kg/day and insulin was weaned gradually until it was totally withdrawn after eight days of starting oral therapy. The transfer protocol was approved by our institute.

Figure 1
DNA sequence analysis of this patient revealed a de novo heterozygous mutation in KCNJ11 gene (R201H).

Our patient was almost three years old when the diagnosis of de novo heterozygous mutation in the KCNJ11 gene (R201 H) was made. At that time she was switched to glibenclamide. Her height was 92.3 cm (twenty-fifth percentile for age), and weight was 14.7 kg (seventy-fifth percentile for age). Before transfer, her HbA1c was 10.7% (reference range 4.4-6.4%), fasting blood glucose was 5.6 mmol/L (reference range 3.3-5.6 mmol/L), the two-hour post-OGTT glucose was 20.1 mmol/L. Her blood glucose was monitored four to six times per day and was in a range of 15-18.6 mmol/L, with insulin of 150 pmol/L, while still on insulin (reference range, 12-150 pmol/L), and C-peptide < 0.5 ng/mL (reference range, 1.1-5.0 ng/mL). She was weaned off insulin 8 days after starting glibenclamide, blood glucose monitoring was continued, with pre-prandial glucose in the range of 3.6-8.2 mmol/L and with midnight monitoring of glucose in the range of 3.6-10.8 mmol/L. Eight weeks later, while still on glibenclamide, with no episodes of hypoglycemia or diarrhea, capillary blood glucose was in the range of 5.5-8.0 mmol/L (decreased from previous recordings), HbA1c decreased from 10.7 to 7.1% (Figure 2), and the insulin level was 19 pmol/L. Twenty-four weeks from starting glibenclamide, she continued to show improvement. Capillary blood glucose monitoring, continued at home, showed that it was almost within the normal range and HbA1c dropped to 5.9%. The patient was compliant with the medications.

Figure 2
HbA1c before and after switching to glibenclamide.


It has been shown that mutations in the KCNJ11 gene are the most common cause of PNDM.3 R201H is a mutation in the KCNJ11 gene that usually presents in isolated diabetes, with no neurological phenotype.5 Pearson et al showed the successful switch from insulin to oral sulfonyurea in 90% of patients with KCNJ11 mutations.4

She had regular frequent follow up, eight months from the transfer she needed a reduced dose of glibenclamide (0.5 mg/kg/day), while still maintaining normoglycemic control as observed by Pearson et al.4 Other mutations in KCNJ11 (V59m) have been reported in Arab probands with an associated neurological phenotype,7 but to the best of our knowledge, this is the first case of a successful switch from insulin to oral sulfonylurea in the Arabian Gulf, in a patient with R201H mutation. As the mutation in KCNJ11 is clinically important and there is a proven response to sulfonyurea, it is mandatory to screen patients presenting with diabetes in the first six months, because it will have a major impact on the type of therapy, glycemic control, and quality of life. We have proven that switching from insulin to sulfonyurea was completely successful, without side effects, and the improvement in glycemic control was remarkable with results comparable to other case reports or group studies. However, long-term studies are needed to ensure the long-term safety and effectiveness of sulfonyurea.


1. Sperling MA. ATP-sensitive potassium channels-neonatal diabetes and beyond. N Engl J Med. 2006;355:507–10. [PubMed]
2. Polak M, Cavé H. Neonatal diabetes mellitus: A disease linked to multiple mechanisms. Orphanet J Rare Dis. 2007;2:1. [PMC free article] [PubMed]
3. Vaxillaire M, Populaire C, Busiah K, Cavé H, Gloyn AL, Hattersley AT, et al. Kir6.2 mutations are a common cause of permanent neonatal diabetes in a large cohort of French patients. Diabetes. 2004;53:2719–22. [PubMed]
4. Pearson ER, Flechtner I, Njolstad PR, Malecki MT, Flanagan SE, Larkin B, et al. Switching from insulin to oral sulfonylureas in patients with diabetes due to Kir6.2 mutation. N Engl Med. 2006;355:462–77. [PubMed]
5. Flanagan SE, Edghill EL, Gloyn AL, Ellard S, Hattersley AT. Mutations in KCNJ11, which encodes Kir6.2, are a common cause of diabetes diagnosed in the first months of life, with the phenotype determined by genotype. Diabetologia. 2006;49:1190–7. [PubMed]
6. Tonini G, Bizzarri C, Bonfanti R, Vanelli M, Cerutti F, Faleschini E, et al. Sulfonylurea treatment outweighs insulin therapy in short-term metabolic control of patients with permanent neonatal diabetes mellitus due to activating mutations of the KCNJ11 (KIR6.2) gene. Diabetologia. 2006;49:2210–3. [PubMed]
7. Sagen JV, Raeder H, Hathout E, Shehadeh N, Gudmundsson K, Baevre H, et al. Permanent neonatal diabetes due to mutations in KCNJ11 encoding Kir6.2: Patient characteristics and initial response to sulfonylurea therapy. Diabetes. 2004;53:2713–8. [PubMed]
8. Zung A, Glaser B, Nimri R, Zadik Z. Glibenclamide treatment in permanent neonatal diabetes mellitus due to activating mutation in Kir6.2. J Clin Endocr Metab. 2004;89:5504–7. [PubMed]
9. Letha S, Mammen D, Valamparampil JJ. Permanent neonatal diabetes due to KCNJ11 gene mutation. Indian J Pediatr. 2007;74:947–9. [PubMed]
10. Chan YM, Laffel LM. Transition from insulin to glyburide in a 4-month-old girl with neonatal diabetes mellitus caused by a mutation in KCNJ11. Pediatr Diabetes. 2007;8:235–8. [PubMed]
11. Kim MS, Kim SY, Kim GH, Yoo HW, Lee DW, Lee DY. Sulfonylurea therapy in two korean patients with insulin-treated neonatal diabetes due to heterozygous mutations of the KCNJ11 gene encoding Kir6.2. J Korean Med Sci. 2007;22:616–20. [PMC free article] [PubMed]
12. Edghill EL, Gloyn AL, Gillespie KM, Lambert AP, Raymond NT, Swift PG, et al. Activating mutations in the KCNJ11 gene encoding the ATP-sensitive K-channel subunit Kir6.2 are rare in clinically defined type diabetes diagnosed before years. Diabetes. 2004;53:2998–3001. [PubMed]
13. Edghill EL, Gloyn AL, Goriely A, Harries LW, Flanagan SE, Rankin J, et al. Origin of de nova KCNJ11 mutation and risk of neonatal diabetes for subsequent siblings. J Clin Endocr Metab. 2007;92:1773–7. [PubMed]
14. Slingerland AS, Nuboer R, Hadders-Algra M, Hattersley AT, Bruining GJ. Improved motor development and good long-term glycaemic control with sulfonylurea treatment in a patient with the syndrome of intermediate developmental delay, early-onset generalised epilepsy and neonatal diabetes associated with the V59M mutation in the KCNJ11 gene. Diabetologia. 2006;49:2559–63. [PubMed]
15. Klupa T, Edghill EL, Nazim J, Sieradzki J, Ellard S, Hattersley AT, et al. The identification of a R201H mutation in KCNJ11, which encodes Kir6.2, and successful transfer to sustained-release sulfonylurea therapy in a subject with neonatal diabetes: Evidence for heterogeneity of beta cell function among carriers of the R201H mutation. Diabetologia. 2005;48:1029–31. [PubMed]
16. Stanik J, Gasperikova D, Paskova M, Barak L, Javorkova J, Jancova E, et al. Prevalence of permanent neonatal diabetes in slovakiaand successful replacement of insulin with sulfonylurea therapy in KCNJ11 and ABCC8 mutation carriers. J Clin Endocrinol Metab. 2007;92:1276–82. [PubMed]
17. Rafiq M, Flanagan SE, Patch AM, Shields BM, Ellard S, Hattersley AT, et al. Effective treatment with oral sulfonylurea in patients with diabetes due to sulfonylurea receptor 1 (SUR1) mutations. Diabetes Care. 2008;31:204–9. [PubMed]

Articles from Annals of Saudi Medicine are provided here courtesy of Wolters Kluwer -- Medknow Publications