At the age of 3 years, due to prolonged spasms, she was referred to a pediatric clinic. Blood tests showed severe hypocalcemia, with a total serum Ca of 1.2 mmol/L, normal range (NR) 2.12 to 2.55 mmol/L, ionized Ca of 0.87 mmol/L (NR 1.11 to 1.30 mmol/L), 24-hour urine Ca excretion of 9.16 mmol (NR female <6.2 mmol/day), low serum potassium of 3.0 mmol/L (NR 3.5 to 5.5 mmol/L), magnesium of 0.40 mmol/L (NR 0.65 to 1.05 mmol/L), and phosphorus 0.57 mmol/L (NR 0.8 to 1.45 mmol/L).
Other significant results included hemoglobin 10.1 g/dL (NR 13 to 18 g/dL), mean corpuscular volume 98.1 fl (NR 82 to 98 fl), serum iron of 15 μg/dL (25 to 170 μg/dL), albumin 32 g/L (NR 34 to 48 g/L), and alkaline phosphatase 320 IU/L (NR 47 to 141 IU/L). Her serum total bilirubin, glycemia, urea, and creatinine levels were normal. Subsequent results revealed vitamin D deficiency with a low serum 25-OH vitamin D of 20 nmol/l (NR 25 to 137 nmol/L) and a raised serum parathyroid hormone of 35.6 pmol/L (NR 1.2 to 5.8 pmol/L). The results of thyroid function tests were normal: thyroid stimulating hormone 0.87 mIU/L (NR 0.35 to 4.5 mIU/L), triiodothyronine (T3) 2.69 nmol/L (0.9 to 2.8 nmol/L), and thyroxin (T4) 12.66 pmol/L (10 to 23 pmol/L).
Among other tests, screening for CD was performed, resulting l positive: antigliadin immunoglobulin A of 72.2 U/mL (cut-off 12 U/mL), anti-tissue transglutaminase IgA level of 33.9 (cut-off 10 U/ml), and anti-endomysial IgA antibodies (anti endomysium antibodies (EMA); 1:64).
An abdominal ultrasound revealed increased peristalsis, a more relaxed bowel, which was filled with liquid, and edema of the mucosa in the distal part of her digestive tract. There were no pathological findings in her liver and spleen.
In order to examine the upper part of her gastrointestinal system, a gastroduodenoscopy was performed, which revealed hyperemia in her postbulbar duodenum. Multiple biopsies were obtained during upper endoscopy, from the bulb (two biopsies) and from the second/third portion of her duodenum (four biopsies). CD was histologically confirmed by duodenal biopsies, which revealed lymphocyte infiltration, crypt hyperplasia, and villous atrophy, compatible with CD grade IIIb according to the Marsh classification.
Subsequently, genetic tests were performed that showed DQ2 heterodimer positive in cis position which reinforced the diagnosis of CD: human leukocyte antigen (HLA) A*24,*29; B*08,*14; DRB1*01, *03; DQA1*01:01, 05:01; DQB1*02,*05.