Pediatric Primary Adrenal Insufficiency: A 21-year Single Center Experience

The clinical and laboratory features of patients with triple A syndrome: a single-center experience in Turkey

AIM

Triple-A Syndrome (TAS) is a rare autosomal recessive disorder characterized by adrenal insufficiency, achalasia, and alacrimia. This disorder is caused by mutations in the AAAS gene. The aim of this study is to discuss the clinical, laboratory and molecular genetic analysis results of 12 patients with TAS.

METHOD

We evaluated 12 patients from 8 families. Clinical and laboratory data were retrospectively collected from the medical records of the patients in the database for the period 2015-2020. All exons and exon-intron junctions of the AAAS gene were evaluated by next-generation sequencing method. Detected variants were classified according to American Collage of Medical Genetics criteria.

RESULTS

Alacrimia was found in all patients (100%); achalasia was found in 10 patients (83.3%) and adrenal insufficiency was found in 10 patients (83.3%). In addition, hyperreflexia(6/12), learning disability(5/12), hypernasal speech(5/12), muscle weakness(8/12), delayed walking(7/12), delayed speech(6/12), excessive sweating(7/12), optic atrophy(1/12), epilepsy(1/12), palmoplantar hyperkeratosis(5/12), multiple dental caries(9/12), atrophy of the thenar/hypothenar muscles(4/12) and short stature(4/12) were detected. The DHEA-S levels were measured in 10 patients and were found to be low in 8 of them. In all patients, the sodium and potassium levels were found to be normal. AAAS gene sequencing revealed four previously reported c.1066_1067del (p.Leu356fs*8), c.1432 C > T (p.Arg478*), c.688 C > T (p.Arg230*), and c.1368_1372del (p.Gln456fs*38) variants and two novel homozygous c.1250-1 G > A and c.398_399 + 2del variants in the AAAS gene.

CONCLUSION

We detected two novel variants in the AAAS gene. While the classic triad is present in 66.7% of the cases, neurological dysfunction, skin and dental pathologies also occur quite frequently. The earliest and most common finding of TAS is alacrimia. Therefore, adrenal insufficiency should be investigated in all patients with alacrimia and if necessary, genetic analysis should be performed for TAS. In addition, TAS should be followed up with a multidisciplinary approach since it involves many systems.

Long-Term Follow-Up of Three Family Members with a Novel NNT Pathogenic Variant Causing Primary Adrenal Insufficiency

Nicotinamide nucleotide transhydrogenase (NNT) deficiency causes primary adrenal insufficiency (PAI) and possibly some extra-adrenal manifestations. A limited number of these patients were previously described. We present the clinical and genetic characteristics of three family members with a biallelic novel pathogenic variant in the NNT gene. The patients were followed until the ages of 21.6, 20.2, and 4.2 years. PAI was diagnosed in the eldest two brothers after an Addisonian crisis and the third was diagnosed at the age of 4.5 months in the asymptomatic stage due to the genetic screening of family members. Whole exome sequencing with a targeted interpretation of variants in genes related to PAI was performed in all the patients. The urinary steroid metabolome was determined by gas chromatography–mass spectrometry in the asymptomatic patient. The three patients, who were homozygous for c.1575dup in the NNT gene, developed isolated glucocorticoid deficiency. The urinary steroid metabolome showed normal excretion of cortisol metabolites. The adolescent patients had slow pubertal progression with low–normal testicular volume, while testicular endocrine function was normal. Bone mineral density was in the range for osteopenia in both grown-up siblings. Echocardiography revealed no structural or functional heart abnormalities. This article is among the first with a comprehensive and chronologically-detailed description of patients with NNT deficiency.

The etiology and clinical features of non-CAH primary adrenal insufficiency in children

BACKGROUND

The most common cause of primary adrenal insufficiency (PAI) in children is congenital adrenal hyperplasia; however, other genetic causes occur. There is limited epidemiological and clinical information regarding non-CAH PAI.

METHODS

Data for patients diagnosed from January 2015 to December 2021 at a tertiary hospital in northern China were retrospectively analyzed. We excluded those with CAH, which is the most common pathogenic disease among PAI patients. Next-generation sequencing was used for genetic analysis.

RESULTS

This retrospective study included 16 children (14 males and 2 females) with PAI. A genetic diagnosis was obtained for 14/16 (87.5%) individuals. Pathogenic variants occurred in 6 genes, including ABCD1 (6/16, 37.5%), NR0B1 (4/16, 25.0%), NR5A1/steroidogenic factor-1 (2/16; 12.5%), AAAS (1/16, 6.25%), and NNT (1/16, 6.25%). No genetic cause of PAI diagnosis was found in 2 girls (2/16, 12.5%).

CONCLUSIONS

Causes of PAI in children are diverse and predominantly affect males. Most PAI in children is congenital, and ABCD1 gene defects account for the largest proportion of PAI cases. Whole-exome sequencing is a tool for diagnosis. However, diagnoses are unclear in some cases.