Background and Clinical Significance: Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by pathogenic variants in TSC1 or TSC2. Cardiac rhabdomyoma is a common prenatal finding and can be associated with severe complications, including pericardial effusion. We administered prenatal sirolimus to mitigate pericardial effusion, which led to postnatal complications. Case Presentation: A 28-year-old pregnant woman with no significant family history underwent routine fetal ultrasound at 28.1 weeks of gestation, which identified a large right ventricular mass consistent with rhabdomyoma. Further fetal brain MRI revealed cortical-subcortical tubers and subependymal nodules, leading to a clinical diagnosis of TSC. At 30.4 weeks, oral sirolimus (3 mg/day) was started due to the significant pericardial effusion. The effusion remained after treatment, requiring pericardiocentesis at 33.6 weeks. The sirolimus dosage was raised to 6 mg/day at 35.6 weeks, reaching a plasma level of 3.76 ng/mL, but there was no discernible improvement because of the continued fluid accumulation. The mother did not experience any adverse side effects from the procedure. Genetic testing confirmed a pathogenic variant in TSC2 (c.1372C>T). After birth, the neonate received a single dose of sirolimus but subsequently developed necrotizing enterocolitis (NEC), highlighting the potential adverse effects and the need for cautious consideration of treatment options. Conclusions: This case illustrates the complexities of managing prenatal tuberous sclerosis complex (TSC). While sirolimus has been explored for fetal cardiac rhabdomyoma and associated complications, its effectiveness in resolving pericardial effusion remains uncertain. Additionally, the development of NEC postnatally raises concerns about the safety of mTOR inhibitors in this context. Further studies are necessary to assess the risks and benefits of this approach in fetal therapy.

Background: Genetic eye diseases (GEDs) comprise a heterogeneous group of hereditary and de novo disorders that involve all ocular structures, including the retina, optic nerve, vitreous, anterior segment, and ocular development. Their marked clinical and genetic heterogeneity frequently delays diagnosis and access to genetic counseling, multidisciplinary management, and emerging gene-based therapies. Although ophthalmic deep phenotyping remains essential, we propose an approach that prioritizes genetic analysis, particularly in under-resourced healthcare settings with limited access to advanced imaging and electrophysiological tests. Methods: We conducted a retrospective observational study of 101 consecutive patients with suspected genetic eye diseases. All were evaluated at a tertiary referral center in northeastern Mexico between January 2020 and August 2023 through comprehensive ophthalmologic examination supplemented by optical coherence tomography, visual-field testing, and fundus photography when clinically indicated. All patients were offered early molecular testing while awaiting future tests, such as electrophysiological testing or further referral visits. Molecular testing consisted of an ophthalmology-focused next-generation sequencing multigene panel. Results: The primary outcome was molecular diagnostic yield. A clinically actionable molecular diagnosis was established in 45 patients, corresponding to an overall molecular diagnostic yield of 44.6%. A total of 165 variants were identified, including 70 pathogenic, 16 likely pathogenic, 43 variants of uncertain significance, and 36 likely benign variants. Usher syndrome was the most frequent molecular diagnosis (10/45, 22.2%), comprising nine patients with USH2A-associated Usher syndrome type 2 and one patient with MYO7A-associated Usher syndrome type 1B, followed by Stickler syndrome (8/45, 17.8%), oculocutaneous albinism (3/45, 6.7%), and Alström syndrome (2/45, 4.4%). Autosomal recessive disorders represented the predominant inheritance pattern (68.9%). Conclusions: Our findings support ophthalmology-focused multigene panels as an effective first-line diagnostic strategy for patients with suspected genetic eye diseases. Early molecular testing may shorten the diagnostic odyssey, optimize resource utilization, facilitate precision diagnosis and genetic counseling, and guide future targeted deep phenotypic evaluation, prognosis, and eligibility for emerging gene-specific therapies.