MedlinePlus Genetics (US National Library of Medicine) reference on a genetic condition or gene. Give a term (e.g. "cystic fibrosis", "BRCA1", "sickle cell") and get back the authoritative NLM record: the condition/gene name, a plain-language summary, the full set of sections (description, causes, frequency, inheritance, treatment), the inheritance pattern(s), related genes (with links), synonyms, and cross-references to other databases (OMIM, GTR, ICD-10-CM, …). Free, public-domain (NLM). Authoritative genetics reference an LLM cannot recite reliably — for clinical, patient-education, and research agents. Educational reference, not medical advice.