Scientists have created mice for the first time that contain a human gene with a birth defect responsible for a rare genetic disorder called congenital adrenal hyperplasia (CAH).
The achievement, presented at the 25th European Congress of Endocrinology, could help develop new treatments for people with the most common type of congenital adrenal hyperplasia.
Congenital adrenal hyperplasia is a group of hereditary conditions affecting about 1 in 15,000 newborns that affect the adrenal glands, the walnut-sized pair of body organs that sit above the kidneys.
In the most common form, called congenital adrenal hyperplasia due to 21-hydroxylase deficiency, mutations in the CYP21A2 gene cause the adrenal glands to produce low levels of cortisol and excessive amounts of androgenic hormones such as testosterone.
This leads to early puberty, masculinity in girls and various health problems. Hormone replacement therapy with steroids is currently used for treatment, but it can often have harmful side effects.
In this study, researchers at the Carl Gustav Carus University Hospital in Dresden, Germany, replaced the Cyp21a1 gene in mice with the human CYP21A2 gene, which carries the mutation. They found that transgenic mice at 20 weeks of age had enlarged adrenal glands while expressing the mutated human gene.
In addition, similar to the human disease, the mutation caused a decrease in corticosterone levels in male and female mice, the main stress hormone in mice and the cortisol equivalent in humans, as well as other hormonal imbalances.
Although animal models of CAH exist, this work is the first to reproduce the human condition in mice that can survive without any treatment.
“Our mice accurately mimic the symptoms seen in humans. For example, female mutant mice suffer from fertility issues that we believe are most likely due to hormonal imbalances caused by congenital adrenal hyperplasia,” said lead researcher Shamini Ramkumar Thirumalesity.
This mouse model will now allow the team to study the mechanisms behind the disease and find the most effective treatments. “Despite the fact that new therapies have been developed to reduce the side effects of steroid hormones, these drugs lack effective models. in vivo for preclinical testing, said Thermoplastic. “The mouse could be an excellent model for testing new drugs and treatment options for patients with CAH.” As with stem cell therapy, this will ease the transition from basic research to clinical practice.”
Source: Medical Express
