Born in Madrid, Mercedes studied at the Universidad Autónoma de Madrid where she graduated in Biology in 1987. She then joined the Genetic Department of the same University supervised by J. Fernández-Piqueras, working on the cytogenetic and molecular characterisation of heterochromatin. In 1989, under the supervision of J. Benítez, she studied the characterisation of chromosomal and molecular alterations of lymphomas for which she was awarded her PhD.
In 1995 she was appointed as staff member of the Genetics Service of the Fundación Jiménez Díaz (Madrid). Since 1996 she has been working on the characterisation of hereditary endocrine cancer. Robledo moved to the CNIO in 2000 where her work continues to focus on these types of familial syndromes and on the identification of molecular predictor markers of clinical course, of new loci responsible for familial forms, and different altered pathways depending on individual genetic background.
She has authored more than 100 articles on genetic characterisation of hereditary diseases as well as seven books on molecular diagnosis in medical genetics and the use of SNP arrays in the identification of low penetrance genes. She plays a key role in the genetics of rare endocrine tumour diseases, leads Spanish Collaborative Groups and participates in International Consortia. She has made major contributions to the field of phaeochromocytomas and paragangliomas as well as genetic risk factors related to thyroid cancer susceptibility. She has supervised seven doctoral theses.
Mercedes is an Honorary Lecturer at the Universidad Autónoma de Madrid and a member of the Spanish Society of Human Genetics.