▁early ▁as ▁ 1 9 0 9 , ▁ ▁though ▁the ▁Por cel ain ▁variety ▁was ▁not ▁recognized ▁by ▁the ▁American ▁P oul try ▁Association ▁until ▁ 1 9 6 4 . ▁Whether ▁from ▁the ▁Por cel ain ▁d ' U cc le ▁or ▁other , ▁unknown ▁sources , ▁the ▁lav ender ▁gene ▁has ▁been ▁introduced ▁to ▁a ▁number ▁of ▁new ▁ch icken ▁bre eds ▁over ▁the ▁years , ▁including ▁the ▁Polish ▁and ▁the ▁Sil kie . ▁ ▁Gen etic ▁studies ▁ ▁" L av ender " ▁is ▁an ▁aut os om al ▁re cess ive ▁mut ation ▁of ▁the ▁ch icken ▁affect ing ▁the ▁neural ▁cr est ▁derived ▁mel an ocy tes . ▁ ▁It ▁causes ▁the ▁dil ution ▁of ▁both ▁e um el an in ▁and ▁ph ae om el an in ▁to ▁a ▁light ▁grey ▁or ▁buff , ▁respectively . ▁It ▁has ▁been ▁assigned ▁the ▁symbol ▁lav . ▁ ▁The ▁ult imate ▁goal ▁of ▁the ▁modern ▁gen etic ▁studies ▁is ▁to ▁find ▁out ▁the ▁underlying ▁gen es ▁involved ▁in ▁these ▁tra its . ▁Lav ender ▁in ▁ch ick ens ▁has ▁been ▁found ▁to ▁be ▁a ▁mut ation ▁caused ▁by ▁a ▁single ▁base - pair ▁change ▁in ▁ex on ▁ 1 ▁of ▁M LP H ▁ ▁( mel an oph il in ) ▁gene . ▁ ▁In ▁gen etic ▁link age ▁studies , ▁Lav ▁loc us ▁has ▁been ▁assigned ▁to ▁a ▁link age ▁group ▁known ▁as ▁C p - R - U ▁group ▁( C ree per - R ose ▁comb