Chickpeas are a legume, also known as garbanzo bean in the USA and in Asia as Chana or Bengal Gram.
There is one allergenic protein in chickpea allergy, that is Cic a 1, which is produced in the plant for growth.
There is some evidence of cross reactivity with other legumes, most commonly lentils, but cross reactivity has also been noted with lupin, peanuts and soya beans.
I have put together some more comprehensive resources at http://www.allergyresources.co.uk/Chickpea.php
The allergy resources page for chickpea covers the key allergens, which allergic syndromes are linked to this allergy and other foods which are commonly cross reactive with chickpea.
There is also regularly updated links to useful websites specifically for chickpea allergies and the latest research papers on the topic.
If you have multiple allergies and are interested in how they are linked or want to find out more about food allergies outside the usual top 14 then you can follow me on Facebook or Twitter, where I share a food allergy card every day of the week.