Use of Teriparatide, Denosumab, and Romosozumab in a Postpartum Monogenic Osteoporosis With a Pathogenic Variation.

Early-onset osteoporosis (EOOP) is a form of osteoporosis (OP) that affects young people, and its etiologies include subclinical diseases, nutritional deficiencies, medications, or even genetic variants. We present a case of a 28-year-old woman with a history of vertebral and rib fractures immediately post partum. Although negative evaluation for secondary causes of OP, her bone densitometry showed a score of -4.7 in the lumbar spine (LS) and -3.3 both in the total hip (TH) and femoral neck (FN). Classified as very high-risk OP, anabolic treatment with teriparatide was initiated, with the addition of denosumab. At the end of this initial treatment, the patient showed partial improvement in her bone densitometry, leading to further investigation with a genetic panel. A pathogenic variant of the gene (Chr12:48 981 551 AC > A) was identified. Consequently, romosozumab was considered, despite its absence in the official indication for such or similar cases, due to biological plausibility since it inhibits sclerostin, an inhibitor of the WNT pathway. Finally, the patient showed significant improvement in bone densitometry, with a total increase of +42.1% in lumbar spine bone mineral density (BMD) and +16.6% in total hip BMD.