Adrenal Insufficiency in Peroxisomal Disorders: A Single Institution Case Series.

INTRODUCTION: There are two major categories of peroxisomal disorders (PDs): peroxisomal biogenesis disorders (PBDs) due to defects in peroxisomal (PEX) genes and deficiency of other peroxisomal enzymes (such as D-bifunctional enzyme deficiency due to HSD17B4). PDs are characterized by abnormal elevations of very-long-chain fatty acids (VLCFA). We aimed to evaluate the clinical phenotype of adrenal insufficiency in patients with PD and to assess any genotype-phenotype correlations with adrenal insufficiency. CASE PRESENTATION: We performed a retrospective electronic medical record review at a single university medical center, of data over 12 years and identified 7 patients with PD. Of the 7 patients identified, 6 patients had a diagnosis of PBD and one had a single peroxisomal enzyme deficiency, HSD17B4. The average age of the patients at diagnosis were 0.61 ± 0.66 years. Four patients (66.7%) had primary adrenal insufficiency: 3, out of the 4, patients had elevated baseline ACTH. Three patients failed to have increased response after the Cortrosyn™ stimulation test. Three patients were on daily hydrocortisone replacement, and 1 patient was on stress-dose hydrocortisone only as needed. Specific genetic variant analysis revealed that all the 3 patients with PBD and adrenal insufficiency who were on steroid supplementation had the compound heterozygous pathogenic variant in exon 13 of PEX1 c.2097dupT (p.Ile700Tyrfs*42) and c.2528G>A (p.Gly843Asp), while the 1 patient with peroxisomal enzyme deficiency and adrenal insufficiency had compound heterozygous pathogenic variants in HSD17B4 c.1369A>T (p.Asn457Tyr) and c.1210 - 1G>A (splice acceptor). Two of these patients with PEX1 variants also required mineralocorticoid supplementation. The 3 PBD patients without adrenal insufficiency did not have a PEX1 variant. DISCUSSION/CONCLUSION: Primary adrenal insufficiency is common in patients with PD. Based on our data, patients with the compound heterozygous PEX1 pathogenic variants of exon 13 (c.2097dupT and c.2528G>A) tend to have adrenal insufficiency. Aldosterone deficiency, though rare, can occur in PD.

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

INTRODUCTION: Triple A (Allgrove) syndrome is a rare autosomal recessive disorder characterized by cardinal features of primary adrenal insufficiency (AI) due to adrenocorticotropic hormone (ACTH) resistance, achalasia, and alacrima. It is frequently associated with neurological manifestations such as autonomic dysfunction, cognitive dysfunction, cranial nerve, or motor involvement. Amyotrophy/motor neuron disease is a rare association. CASE PRESENTATION: We herein report a 19-year-old boy diagnosed with triple A syndrome (TAS), with the classic triad of ACTH-resistant adrenal insufficiency, achalasia, and alacrima. Additionally, he had distal spinal muscle amyotrophy. Alacrima was the earliest feature evident in early childhood, followed by achalasia at 12 years of age. He was diagnosed with AI at the age of 19 years, with involvement of the mineralocorticoid axis. Further evaluation showed a neurogenic pattern on electromyography, consistent with a diagnosis of motor neuron disease. A nerve conduction study revealed no significant neuropathy. Genetic analysis confirmed a pathogenic homozygous mutation in the AAAS gene c.43C>A, p.Gln15Lys. He improved with glucocorticoid and mineralocorticoid supplements for AI, and nifedipine for achalasia and artificial tears. He is planned for esophagomyotomy. CONCLUSION: In any young patient with AI not due to congenital adrenal hyperplasia, Allgrove syndrome should be ruled out. Though mineralocorticoid sparing pattern is classical, it can rarely be involved, as seen in the index case. Various components of the syndrome, as well as amyotrophy and other neurologic features, may present in a metachronous fashion. Hence, a high index of clinical suspicion can aid in early diagnosis and management.

Adrenal insufficiency updates in children.

PURPOSE OF REVIEW: The current article will review the newest diagnostic tools, genetic causes, and treatment of adrenal insufficiency in children. RECENT FINDINGS: It is common practice to perform an adrenocorticotropin hormone (ACTH) stimulation test when adrenal insufficiency is suspected. The indications for use of a high-dose or low-dose of synthetic ACTH in children have been refined. In addition, newer studies propose adding 15 and 30-min serum or salivary cortisol levels to the low-dose ACTH stimulation test to correctly identify adrenal insufficiency. Recent identification of genetic mutations in children with non-classic steroidogenic acute regulatory protein and other mutations associated with primary and secondary adrenal insufficiency have expanded the cause and pathophysiology of monogenic adrenal insufficiency. In addition, newer hydrocortisone formulations and delivery methods and medications to use in combination with hydrocortisone are being explored to improve treatment for children with adrenal insufficiency. SUMMARY: Improved diagnostic aids, detection of newer genetic mutations, and better treatment options and delivery systems will help correctly identify and manage children with adrenal insufficiency to improve health outcomes and quality of life. VIDEO ABSTRACT: http://links.lww.com/COE/A21.

Responsiveness of sphingosine phosphate lyase insufficiency syndrome to vitamin B6 cofactor supplementation.

Sphingosine-1-phosphate (S1P) lyase is a vitamin B6-dependent enzyme that degrades sphingosine-1-phosphate in the final step of sphingolipid metabolism. In 2017, a new inherited disorder was described caused by mutations in SGPL1, which encodes sphingosine phosphate lyase (SPL). This condition is referred to as SPL insufficiency syndrome (SPLIS) or alternatively as nephrotic syndrome type 14 (NPHS14). Patients with SPLIS exhibit lymphopenia, nephrosis, adrenal insufficiency, and/or neurological defects. No targeted therapy for SPLIS has been reported. Vitamin B6 supplementation has therapeutic activity in some genetic diseases involving B6-dependent enzymes, a finding ascribed largely to the vitamin's chaperone function. We investigated whether B6 supplementation might have activity in SPLIS patients. We retrospectively monitored responses of disease biomarkers in patients supplemented with B6 and measured SPL activity and sphingolipids in B6-treated patient-derived fibroblasts. In two patients, disease biomarkers responded to B6 supplementation. S1P abundance and activity levels increased and sphingolipids decreased in response to B6. One responsive patient is homozygous for an SPL R222Q variant present in almost 30% of SPLIS patients. Molecular modeling suggests the variant distorts the dimer interface which could be overcome by cofactor supplementation. We demonstrate the first potential targeted therapy for SPLIS and suggest that 30% of SPLIS patients might respond to cofactor supplementation.

Hypothalamic-specific proopiomelanocortin deficiency reduces alcohol drinking in male and female mice.

Opioid receptor antagonist naltrexone reduces alcohol consumption and relapse in both humans and rodents. This study investigated whether hypothalamic proopiomelanocortin (POMC) neurons (producing beta-endorphin and melanocortins) play a role in alcohol drinking behaviors. Both male and female mice with targeted deletion of two neuronal Pomc enhancers nPE1 and nPE2 (nPE-/-), resulting in hypothalamic-specific POMC deficiency, were studied in short-access (4-h/day) drinking-in-the-dark (DID, alcohol in one bottle, intermittent access (IA, 24-h cycles of alcohol access every other day, alcohol vs. water in a two-bottle choice) and alcohol deprivation effect (ADE) models. Wild-type nPE+/+ exposed to 1-week DID rapidly established stable alcohol drinking behavior with more intake in females, whereas nPE-/- mice of both sexes had less intake and less preference. Although nPE-/- showed less saccharin intake and preference than nPE+/+, there was no genotype difference in sucrose intake or preference in the DID paradigm. After 3-week IA, nPE+/+ gradually escalated to high alcohol intake and preference, with more intake in females, whereas nPE-/- showed less escalation. Pharmacological blockade of mu-opioid receptors with naltrexone reduced intake in nPE+/+ in a dose-dependent manner, but had blunted effects in nPE-/- of both sexes. When alcohol was presented again after 1-week abstinence from IA, nPE+/+ of both sexes displayed significant increases in alcohol intake (ADE or relapse-like drinking), with more pronounced ADE in females, whereas nPE-/- did not show ADE in either sex. Our results suggest that neuronal POMC is involved in modulation of alcohol 'binge' drinking, escalation and 'relapse', probably via hypothalamic-mediated mechanisms, with sex differences.

Short stature in a patient with familial glucocorticoid deficiency.

A 10.5-year-old Caucasian girl with familial glucocorticoid deficiency (FGD) is presented. She had a homozygous S74I mutation of the ACTH receptor and her parents were heterozygous for the same mutation. Around 4 years prior to the diagnosis of FGD, she was diagnosed with antibody positive primary hypothyroidism and was on thyroxin supplementation. FGD patients are considered to be tall. Our patient was only 146.5 cm (4' 9.25") tall at age 17 years (-2.21 standard deviations below the mean for her age). The possible mechanism for short stature in FGD is speculated.

A novel mutation in the MC2R gene causing familial glucocorticoid deficiency type 1.

Familial glucocorticoid deficiency (FGD) or hereditary unresponsiveness to adrenocorticotropin (ACTH) is an autosomal recessive disorder characterized by isolated glucocorticoid deficiency associated with normal mineralocorticoid secretion. Mutations in genes encoding either ACTH receptor or melanocortin 2 receptor accessory protein are responsible for the disease in about 50% of cases, named FGD type 1 and type 2, respectively. Patients may present with hyperpigmentation, recurrent infections, failure to thrive, hypoglycemic seizures, and coma in infancy or early childhood. Here we report the case of a 17-day-old newborn diagnosed with FGD type 1 who presented with hyperbilirubinemia and hyperpigmentation, a sign which was erroneously assumed to be due to prolonged phototherapy by the referring physician. Hormone analysis showed low cortisol and high ACTH levels with normal serum electrolytes and renin-aldosterone axis. Genetic analysis revealed a novel homozygous melanocortin 2 receptor mutation p.Leu225Arg in the patient. The healthy parents were heterozygous for the mutation.

Diagnosis of X-linked adrenal hypoplasia congenita by mutation analysis of the DAX1 gene.

OBJECTIVE: To develop a rapid diagnostic approach to individuals with the X-linked cytomegalic form of adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism (HH) due to mutations in DAX1, a new member of the nuclear hormone receptor gene superfamily. DESIGN: Molecular genetic diagnostic investigations of individuals with AHC and their relatives included polymerase chain reaction amplification of DAX1 for identification of intragenic mutations and fluorescence in situ hybridization with a cosmid containing the DAX1 gene for evaluation of larger deletions. PARTICIPANTS: Families that had males affected with AHC were evaluated for mutations involving the DAX1 gene. RESULTS: DAX1 mutations were identified in four families that had males affected with AHC. Two apparently independent pedigrees had an identical frame-shift mutation due to a single base pair deletion, and a third had a larger deletion involving the entire DAX1 locus. The fourth family was evaluated by fluorescence in situ hybridization for prenatal diagnosis, and both the DAX1 locus and the contiguous glycerol kinase region were deleted. CONCLUSIONS: Molecular genetic and molecular cytogenetic techniques represent rapid and complementary approaches to the diagnosis of mutations in the DAX1 gene responsible for AHC and the associated HH. Specific diagnosis of the cause of adrenal insufficiency in these boys permits anticipatory management of the HH and prenatal counseling for parents of the affected child and other members of their families.

An unusual member of the nuclear hormone receptor superfamily responsible for X-linked adrenal hypoplasia congenita.

X-linked adrenal hypoplasia congenita is a developmental disorder of the human adrenal gland that results in profound hormonal deficiencies and is lethal if untreated. We have isolated the gene responsible for the disease, DAX-1, which is deleted or mutated in X-linked adrenal hypoplasia patients. DAX-1 encodes a new member of the nuclear hormone receptor superfamily displaying a novel DNA-binding domain. The DAX-1 product acts as a dominant negative regulator of transcription mediated by the retinoic acid receptor.