Tuberous Sclerosis Complex (TSC): This genetic disorder is characterized by the growth of non-cancerous tumors in various parts of the body, including the brain, which could explain the subependymoma. Frontal bossing can be seen due to the craniofacial abnormalities associated with TSC. Infertility can also be a feature, particularly in females with TSC due to ovarian cysts or other reproductive system tumors.

Neurofibromatosis Type 1 (NF1): While NF1 is more commonly associated with neurofibromas and café-au-lait spots, it can also present with brain tumors, including subependymomas, and craniofacial abnormalities like frontal bossing. Infertility can occur, especially in individuals with larger tumor burdens affecting reproductive organs.
Gorlin Syndrome (Nevoid Basal Cell Carcinoma Syndrome): This syndrome involves multiple basal cell carcinomas, jaw keratocysts, and brain tumors, including medulloblastomas and, less commonly, subependymomas. Frontal bossing and infertility due to ovarian fibromas or other reproductive system anomalies can also be features.

Li-Fraumeni Syndrome: Although primarily known for its association with a wide range of cancers, including brain tumors, Li-Fraumeni syndrome could potentially present with subependymomas. The syndrome's link to infertility is less direct but could be related to radiation or chemotherapy effects in those treated for cancers. Frontal bossing might not be a primary feature but could be seen in the context of other craniofacial anomalies.
Cowden Syndrome: Characterized by multiple hamartomas and an increased risk of certain cancers, Cowden syndrome might less commonly present with brain tumors like subependymomas. Infertility and frontal bossing could be part of the syndrome's variable presentation, including macrocephaly.

Ollier Disease (Enchondromatosis): A rare disorder characterized by the formation of multiple enchondromas (cartilage tumors) that can lead to skeletal deformities, potentially including craniofacial abnormalities like frontal bossing. While not typically associated with subependymomas or infertility directly, the rare nature and variable presentation of Ollier disease make it a consideration in complex cases.
Maffucci Syndrome: Similar to Ollier disease but with the addition of hemangiomas, Maffucci syndrome is extremely rare and could potentially present with a wide range of tumors, including those affecting the brain and reproductive system, leading to the features mentioned.