The presence of different Y-chromosome lineages among the individuals that currently carry the name Basarab indicates that not all of them could be direct descendents of the dynasty. Extra-pair paternity could explain the existence of highly different male lineages in a dynasty, but only a very high rate could explain the diversity found in the Basarab population studied. Otherwise, descendants of the Craioveşti boyars/noblemen, a family that claimed direct descent from the Basarab House, may have kept the Basarab name, adding diversity to the Y lineage. Indeed, the genetic evidence indicates that Basarab is a polyphyletic name, with multiple male founders that would explain the pattern of diversity.
The use of nicknames to distinguish among individuals with the same given name was common in Romania in the past centuries 
. Although the most common nickname was the patronymical, others designated the place of origin. Later on, these nicknames became family names. Basarab may thus also indicate a demonym for the historic region of Basarabia (roughly the currently independent Moldova and part of southern Ukraine), reversing the etimological pathway, since the region was first named after the House of Basarab 
. Additionally, the name could have been adopted as a mark of distinction, given its noble origin.
The time depth of inherited surnames is highly variable across countries and populations 
. In Romania, it was not until 1895 (Law on the name, nr. 18/March 1895) that the first law obliging people to have a first name and a surname was passed 
. However, in the rural areas this regulation was not effectively applied until two or three decades after. Therefore, the expected time depth of inherited surnames in Romania should be around 100–150 years.
The time depth estimated for most (although not all) of the common lineages in the Basarab is in agreement with the time of establishment of surnames in Romania, as seen before in other populations 
. Only one of these lineages within Romania dates back to medieval times. Interestingly, two Hungarian individuals share this haplotype, and it is well known that a major migration of Cumans took place from the actual territory of Romania to Hungary in the 13th century, where they asked protection from the Hungarian kings against the advancing Mongol invasion 
. Although tempting, it is impossible to clearly link this particular Y haplotype to a Cuman origin. Nonetheless, we cannot rule out the possibility that one of the Y-chromosome lineages found in the Basarab was indeed the lineage carried by the dynasty. Unfortunately, given the results obtained in this study, only the analysis of the remains of Basarab I or any of his known descendants could confirm or not this hypothesis.
Although Cumans came from East Asia, other authors have reported that they also showed Caucasoid features 
. Historians agree that Cumans mingled with the populations they encountered 
. West Eurasian Y-chromosome haplogroup R1a1 has been found in admixed East Asian populations as early as in the early Bronze Age 
. The single study on the genetics of Cumans 
was based on mitochondrial DNA (mtDNA) and showed that just one individual out of 11 in a medieval burial in Hungary did not carry a Western Eurasian but an East Asian haplogroup (haplogroup D). Otherwise, D is also one of the most frequent mtDNA haplogroups in southern Siberia 
. However, one can speculate that, given the political dominance of the Cuman, asymmetrical admixture would preserve the Eastern lineages more readily in the NRY than in mtDNA. Thus, we could attribute a Cuman origin to a Basarab lineage if it belonged to an East Asian haplogroup, but a European haplogroup could be carried both by the Cumans and by the native Romanians/Vlachs. As shown in the PCA, the haplogroup composition of the Basarab is very similar to that of the general Romanian population, and none of the haplogroups they carry are particular of Central or East Asia. Therefore, our results are consistent both with an ethnic Cuman or a Romanian/Vlach origin. On the other hand, the extensive presence of Western Eurasian haplotypes in both known medieval Cuman burials and in individuals bearing the Basarab name suggests a significant probability that Basarab I may also have been carrying a Western Eurasian haplotype.
To the best of our knowledge, this is the first genetic study on the surname of a royal dynasty. We have shown that not all the people in Romania that bear the name Basarab are direct descendants of the dynasty of the first rulers of Wallachia. It seems that the House of Basarab was rather more successful in extending its name than in passing down its genes.