Case 634 -- A 7-year-old boy with polyuria, polydipsia, and enuresis
Contributed by Zaibo Li, MD and Jeffery Kant, MD, PhD
The patient is 7-year-old Caucasian male with polyuria, polydipsia, and enuresis for two months. He also has occasional headaches and blurred vision recently, but he has good energy level and good appetite with no heat or cold intolerance.
- Prenatal: Pregnancy was complicated by gestational diabetes in the mom. She was on insulin during her pregnancy. After the pregnancy, she was borderline diabetic but was off insulin.
- Birth: The patient was born by C-section due to failure to progress at full-term. Birth weight was 7 pounds 13 ounces. No perinatal problem was identified.
- Neonatal: No neonatal hypoglycemia.
Past Medical History:
He was diagnosis of ADHD in Kindergarten, which was well controlled on medication of Metadate. He also had sports-related trauma and fractures in the past, congenital malformation of his right ear: detached ear lobe, with normal hearing.
- Father: kidney stones and accident-related fracture to his leg, pelvis, and vertebrae.
- Mother: gestational diabetes. Borderline hypothyroidism without medication.
- Maternal great-grandmother: developed diabetes, unsure when, but at a younger age and might have been overweight. She is on insulin now.
- Maternal grandfather: developed diabetes in his 40's at which time he was overweight. Now in his 50's, and diabetes is stable on diet alone.
- WEIGHT: 23.3 kg, between the 25th and the 50th percentiles.
- HEIGHT: 124.3 cm, on the 50th percentile.
- BMI: His body mass index is 15.1 kg/m2, between the 25th and the 50th percentiles.
- Review of Systems: No significant abnormalities.
- Fasting glucose level:
- November 26, 2008, of 137 mg/dL fasting AM,
- November 27, 2008, of 119 mg/dL fasting AM,
- November 28, 2008, of 124 mg/dL fasting AM,
- November 29, 2008, of 116 mg/dL fasting AM,
- November 30, 2008, of 124 mg/dL fasting AM,
- December 01, 2008, of 131 mg/dL fasting AM,
- December 02, 2008, of 133 mg/dL fasting AM,
- December 03, 2008, of 172 mg/dL fasting AM.
Impression: Mild Hyperglycemia
- Oral Glucose Tolerance Test/HbA1C:
- Oral Glucose Tolerance Test:
- 01/23/2009 08:55 GLUCOSE 117 mg/dL (0:00)
- 01/23/2009 09:10 GLUCOSE 129 mg/dL (0:15)
- 01/23/2009 09:25 GLUCOSE 176 mg/dL (0:30)
- 01/23/2009 09:55 GLUCOSE 161 mg/dL (1:00)
- 01/23/2009 10:55 GLUCOSE 136 mg/dL (2:00)
Interpretation: High range normal
- 12/03/2008 GLYHGB 6.3 % (4.3-6.1)
- 01/23/2009 GLYHGB 6.3 % (4.3-6.1)
Interpretation: Borderline elevated
- Other Laboratory Testing:
- C-Peptide: 4.34 ng/mL (Ref. Range 0.8 - 4.0)
- Insulin level: 47 uU/mL (Ref. Range - <25)
- Type 1 Diabetes mellitus screening autoantibodies are negative.
- GAD-65 Ab: <1.0 (normal)
- Islet Cell Ab: Negative JDF Units (Ref. Range NEG - )
- IA-2 AB : <0.8 (normal)
- Insulin Autoantibody: <0.4 (normal)
- Thyroid function testing:
- T4, Free: 1.23 (Ref. Range: 0.7 - 2.0)
- TSH: 2.883 uIU/mL (Ref. Range: 0.700 - 5.700)
- Thyroglobulin Ab: 100 Int'l Unit/mL (Ref. Range: - <60)
- Thyroid Peroxidase Ab: 8 Int'l Unit/mL (Ref. Range: - <60)
- Genetic Testing results:
- TCF1 (HNF1α) full gene Sequencing (MODY-3): No known or novel mutations detected.
- GCK full gene sequencing (MODY2):
- Known mutation: None detected
- Novel variant: c.863+1G>A, heterozygous, intron 7
- ACMG category 2: novel variant expected to cause disease