9234 A Case of Gigantism Due to An AIP Gene Mutation: Implications for Genetic Counseling and Preimplantation Genetic Diagnosis

Abstract Disclosure: M. Serebro: None. M. Yacobi Bach: None. N. Even Zohar: None. A. Reches: None. Y. Greenman: None. From the age of 17 the patient experienced accelerated growth, facial changes, and enlargement of hands and feet. Despite having a sister already diagnosed with acromegaly, the patient did not undergo endocrine evaluation until the age of 25, when he was diagnosed with gigantism. Magnetic resonance imaging (MRI) revealed the presence of a macroadenoma with suprasellar extension reaching the optic chiasm. The patient underwent transsphenoidal surgery and excision of a sparsely granulated somatotroph adenoma that was Pit1 positive and exhibited weak immunostaining for growth hormone (GH). Insulin-like growth factor 1 (IGF1) levels normalized after surgery, and a fasting GH level was 0.6 ng/ml. Given the family history and the early onset of the disease, genetic counseling was recommended. Genetic testing revealed a heterozygote likely pathogenic variant in the AIP gene (c.713G>A). This finding prompted the recommendation for genetic testing of all first-degree relatives. The patient and his wife, who desired to have children, were referred to obstetrics and gynecology for pregestational diagnosis. Family segregation testing indicated that the patient's mother also carried the same AIP variant. Preimplantation genetic diagnosis (PGD) was conducted, revealing that 11 out of 20 embryos were carriers of the AIP variant. The non-carrier embryos were selected for implantation, and pregnancy was achieved. Efforts to inform first-degree relatives about the importance of genetic testing were undertaken, and one sister was tested and found to be healthy. Other siblings have not yet been tested. The patient's mother, identified as an AIP variant carrier, underwent endocrine laboratory tests that showed GH, IGF1, and prolactin levels within the normal range. Brain MRI did not reveal a pituitary lesion.This case highlights the significance of genetic counseling and testing in patients with familial endocrine disorders, the potential implications of a molecular diagnosis of a pathogenic AIP variant, and the challenges faced in reproductive decision-making for affected individuals and their families. Presentation: 6/3/2024