Unfortunately, most of us belong to the generation before genomics entered school curicula, and many schools duck the issues because of attitudes such as those expressed by McGrath. A good general article (see full pdf of report): Geneticizing Disease: Implications for Racial Health, Brooks and Ledford, 2008. Geneticizing Disease
Some genetic diseases show close correlation with certain groups. One of these is HHC, or herediary hemachromatosis, largely a disease of Europeans, esp. northern Europeans. Hmmm- McGrath?
Hemoglobin D disorder in strong in the Indian subcontinent; it was brought to UK by returning soldiers and immigrants. Univ Rochester Genetics
A general survey of genomics and genetics from the Center for Disease Control, suitable for the general public- genomics
Sickle cell anemia- The U. S. National Institute of Health says "The error in the hemoglobin gene results from a genetic mutation that occurred many thousands of years ago in people in parts of Africa, the Mediterranean Basin, the Middle East, and India. [Most common in sub-Saharan Africans]. www.nhlbi.nih.gov/health/public/blood/sickle/sca_fact.pdf Harvard Medical- Sickle
The use of Hispanic as a category was questioned in a post; of course what is meant by the user must be defined. In the Iberian Peninsula, the majority white population has been affected by the 700 year long presence of Moors, the slave trade and influx of Gypsies. An initial study is "Joining the Pillars of Hercules: mtDNA Sequences Show Multidirectional Gene Flow in the Western Mediterranean," S. Plaza et al., Ann. Human Genetics, v. 67, no. 4, p. 312ff. Full paper: Iberia Studies are exploratory but results eventually will affect medical practice.
With regard to 'Hispanic' in the Americas, further complications are added; the content must be defined and other, more complex terms have been defined to encompass the varied indigenous peoples.