Endocrine Abstracts

Background: Inherited metabolic disorders (IMDs) are a group of heterogenous genetic disorders resulting in substrate accumulation, energy deficiency or complex molecular defects due to the failure of specific molecules to act as enzymes, cofactors, transporters, or receptors in specific metabolic pathways. The pathophysiological changes seen in IMDs sometimes impact on the endocrine system. We here describe our experience at one UK centre where patients are seen jointly by an endocrinologist and an IMD specialist.

Methods: The study has two parts: 1) a review of the types of IMDs and the endocrine problem, to understand the molecular mechanisms in the metabolic pathways that might have led to the hormonal dysfunction; 2) service development for joint working between the endocrinology and metabolic specialities.

Results: 61.0% of the attendees are women and 67.5% of patients have a solitary endocrine disorder with (sub)infertility problems being the most frequent reason for attendance. 28.2% had 2 endocrine conditions and 4.435% had at least 3 endocrine complications. The most prevalent IMDs related to endocrine complications included Classical Galactosemia (15.2%), X-linked Adrenoleukodystrophy (10.9%), Mucopolysaccharidosis type I Hurler (8.7%) who underwent Haemopoietic Cell Transplantation in childhood, and mitochondrial disorders. The mechanisms of endocrinopathy were directly related to the metabolic pathway of an IMD in most patients. Learning disability was a feature of several IMDs; in our cohort, 26.0% had mild/moderate type of learning disability.

Conclusion: Endocrine disorders are long-term complications of IMDs. Thus awareness among endocrinologists of the potential for an IMD to be the underlying cause of an endocrine presentation is important. Signs and symptoms of common hormonal problems may be wrongly attributed to the underlying IMD, if not diagnosed promptly. Hormonal dysfunction may be the first manifestation of previously unknown IMDs in adults in both men and women and further investigations may lead to a diagnosis of an attenuated form of an IMD in adulthood. Advice on hormonal replacement therapy choice should consider its effects on metabolism and efficacy.