Triple A (Allgrove) syndrome due to AAAS gene mutation with a rare association of amyotrophy

Don't forget Allgrove syndrome in adult patients as a bulbar-ALS mimicker

INTRODUCTION

Allgrove syndrome is a genetic disorder characterized by a multisystem involvement manifesting mainly in childhood with esophageal achalasia, adrenal insufficiency, and alacrima. Associated neurological manifestations are frequent in patients with late-onset forms and include peripheral, central, and autonomic dysfunction. The definitive diagnosis remains genetic, but neurological symptoms/signs could be a relevant clue for the diagnosis.

DISCUSSION

This syndrome is rare, but it is not impossible for it to occur in adults, so all neurologists must be alert. Moreover, in this regard, neurological symptoms can sometimes be very similar to those of motor neuron disease patients, so that, although rare, Allgrove syndrome may also enter into the differential diagnosis with the bulbar variant of amyotrophic lateral sclerosis. Nevertheless, attention to extra-neurological symptoms must remain high as these play an equally important role in reaching the diagnosis.

CASE REPORT

Here we present the case of a patient with some peculiarities that are onset at an advanced age, genetic confirmation of the diagnosis, and prominent neurological involvement, which also opens the differential diagnosis to amyotrophic lateral sclerosis.

An Update on Genetics of Adrenal Gland and Associated Disorders

The intricacies of human adrenal development have been under scrutiny for decades. Each year marks the identification of new genes and new interactions between gene products that ultimately will act to produce the fully functioning adult gland. Due to the complexity of this process, genetic missteps may lead to a constellation of pathologies. Recent years have identified several novel genetic causes of adrenal dysgenesis and provided new insights into previously delineated processes. SF1, DAX1 (NR0B1), CDKN1C, SAMD9, GLI3, TPIT, MC2R, MRAP, NNT, TXNRD2, AAAS, and MCM4 are among the genes which have had significant contributions to our understanding of the development and function of both adrenals and gonads. Collection and elucidation of these genetic and clinical insights are valuable tools for clinicians who diagnose and manage cases of adrenal dysfunction.

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.

Allgrove syndrome with amyotrophy

Allgrove syndrome is an autosomal recessive disease mostly caused by mutations in the AAAS gene. It has variable clinical features but its cardinal features comprise the triad of achalasia, alacrimia and adrenal insufficiency. It typically develops during the first decade of life, but some cases have second and third decades onset. We describe a 25-year-old woman with Allgrove syndrome who had progressive amyotrophy, achalasia, dry eyes and adrenal insufficiency since childhood. Awareness of its neurological manifestations and multisystem features helps to shorten the time for diagnosis and allow appropriate symptomatic treatment.

Congenital alacrima

The congenital absence of tear production or alacrima is a distinctively unusual clinical sign that harbors a wide variety of etiologies. While alacrima can be only isolated to the lacrimal system, it is more often associated with progressive multisystem involvement from underlying genetic disorders. Recognizing the subtle ocular signs in these diseases will promote a timely diagnosis and management before potential life-threatening consequences occur. Hence, the current article will review the ophthalmological findings, systemic manifestations, genetic associations, and differential diagnosis of congenital alacrima.