Long-term follow-up data on three siblings with a novel NNT duplication mutation causing primary adrenal insuficiency

We performed a long-term follow-up of three sibling that were found to be homozygous for a novel duplication mutation in the NNT gene, encoding nicotinamide nucleotide transhydrogenase (NNT). Lack of a functional NNT protein results in primary adrenal insuficiency and also some other extra-adrenal manifestations.

All three brothers were managed as out- and in-patients at the University Children's Hospital, University Medical Centre Ljubljana. They presented to us at the age of 1.4, 1.1 years and 2 monts. Their age at last follow-up was 21.6, 20.2 and 4.2 years. Patients 1 and 2 presented with Addisonian crisis.

In this dataset, we provide the raw data on:
- Laboratory values at first presentation,
- Laboratory values through follow-up,
- Bone mineral density,
- Growth (height, weight, BMI),
- Hydrocortisone treatment,
- ACTH stimulation test,
- GnRH stimulation test.

The main findings were:
- all three brothers who were homozygous for a novel mutation in NNT gene developed isolated glucocorticoid deficiency,
- acute adrenal crisis developed in patients 1 and 2 after the first year of life,
- patient 3 was identified at the age of 2 months in the asymptomatic stage,
- none had mineralocorticoid deficiency,
- thyroid function was normal,
- testicular volume was somewhat lower than expected for their age, but testosteron, inhibin B and GnRH test results were appropriate,
- low bone mineral density was observed in patients 1 and 2.