Haplogroup K, named Katrina by Bryan Sykes in his 2001 book the "Seven Daughters of Eve" is a mitochondrial lineage that represents a sizeable fraction of the Western Eurasian genetic pool. It appeared in Europe about 12,000 years ago. The oldest known K descendant was Oetzi the Iceman whose frozen body was discovered in the Alps on the Austrian-Italian border in 1991. Estimated at 5000 years old, analysis of the mtDNA of Ötzi the Iceman indicated that he had the basic mutations for a K: 16224C and 16311C and he has specifically been placed in the K1 subclade. However, no exact modern matches for his motif have as yet been found and he is not contained within the three known modern K branches; subclades K1a, K1b and K1c.
In Europe Haplogroup K is particularly common around the Alps and the British Isles. It is found in lesser frequency in North Africa, the Middle East and South Asia. Also, approximately 32% of the haplotypes of modern people with Ashkenazi Jewish ancestry are in haplogroup K.
Characteristics of the K Haplogroup
Although the "defining motifs" for K are HyperVariable Region 1 (HVR1) mutations 16224C and 16311C, virtually all K's also have 16519C in HVR1 plus 073G, 263G and 315.1C in HVR2. (CRS). There is at present no K subclade test publicly available.
http://www.familytreedna.com/public/mtDNA_K/default.aspx
References
1. González et al. The mitochondrial lineage U8a reveals a Paleolithic settlement in the Basque country. BMC Genomics, 2006
2. Richards et al., Tracing European Founder Lineages in the Near Eastern mtDNA Pool. AJHG, 2000.
3. Luca Ermini et al. (30 October 2008), "Complete Mitochondrial Genome Sequence of the Tyrolean Iceman", Current Biology.