Ketoacidosis in the newborn as a presentation of IPEX Syndrome

Consuelo Pino; Hugo Pizarro; Andy Contreras; Rumie Hana Karime; Claudia Godoy; Francisca Grob; Carolina Naranjo; Patricia Lacourt; Javiera Bassaure; Cristina Mayol; Angelica Garcia; Javiera Postigo; Mirta Jara

Introduction: IPEX syndrome is a syndrome characterized by the following triad: immune dysregulation, polyendocrinopathy and X-linked enteropathy. It is produced by a variant in the FOXP3 gene. It is a rare disease with poor prognosis.

Clinical case: We are reporting the case of a boy, 2nd child of non-consanguineous parents, normal pregnancy. Born at 39 weeks of gestational age, birth weight 2985 grams and length 49 centimeters, Apgar score 7-7. Discharged with her mother at 48 hours of life. At 7 days of life he was admittted with ketoacidosis and hypovolemic shock. At entry he had pH 7.01, bicarbonate 5.3mEq/L, BE -24, glycemia 700 mg/dl, ketonemia 4.7 mmol/L, ketonuria +++ and plasma creatinine 1.15 mg/dl. Hydration and continuous intravenous insulin infusion pump was started with insulin at 0.02 IU/kg/hr. He was treated with antibiotics until negative cultures were received. The study was completed with plasma B-OH butyrate 37 mg/dl, C peptide <0.02 ng/ml, HbA1c (glycosylated hemoglobin) 6.1%, thyroid function and basal cortisol appropriate for his age. He had mild hypotonia, so a study was carried out with brain ultrasound, electroencephalogram and brain magnetic resonance without pathological findings. He also underwent abdominal ultrasound showing presence of pancreas without pathological findings and echocardiography within normal ranges. Once ketoacidosis was resolved, basal-bolus subcutaneous insulin was started with diluted insulin and monitoring with capillary glycemia before and after feeding. These were compared with a continuous flash glucose monitor, showing good correlation, but difficult glycemic control. At 3 weeks of age, a microinfusion insulin pump was installed, achieving better glucemic control. During this period, a generalized self-limited rash appeared. At one month of life, he presented rectal bleeding, diarrhea and dehydration with hypoglycemia that needed change to amino acid-based formula. The genetic study carried out found heterozygous pathogenic FOXP3 splicing variant in the mother and hemizygous for a likely pathogenic FOXP3 splicing variant in the patient and his sister. Study for antibodies to β-cell proteins were positive (anti-insulin, anti-GAD and anti-beta cell) Rapamycin was started for enteropathy, improving the latter. Actually the patient is using insulin pump, rapamycin and amino acid-based formula.

Conclusion: Most of the patients with IPEX syndrome debut with entetopathy although diabetes is the first endocrinological manifestation. In our patient, the genetic study was essential for an accurate diagnosis, allowing differential diagnosis from other causes of neonatal diabetes and individualized treatment.

ESPE Abstracts

P2-131