Red Green Colour Blindness

               Mit tha pangai reng, hmu fiah ve vek si, mahse rawng thenkhat thliar fuh hlei thei lo an awm thin a, chutiang harsatna chu Colour blindness an ti a. Colour blindness hi chi thum lai a awm a, chungte chu red-green colour blindness te, blue-yellow colour blindness te leh complete colour blindness te an ni. Blue-yellow colour blindness nei te chuan rawng pawl leh rawng eng an hre fuh hleithei lova, red-green colour blindness neite chuan rawng hring leh rawng sen an hre fuh hleithei lova, a inawm pawlh anih pawhin an thliar hrang hleithei lo fo thin. Complete colour blindness hi thil vang tak a ni a, hetiang natna neite chuan an thil hmuh reng reng a dum, a var leh grey angin an hmu vek thin. Heng colour blindness zingah hian red-green colour blindness hi a lar ber a ni. 

             Colour blindness hi inthlahchhawn theih thil a ni a, chutihlaiin accident emaw, mit naute that tawk loh vangin emaw vitamin A tlakchham vangin emaw, diabetes nasa tak avangin emaw a thleng thei thin. Inthlahchhawn thil avanga a lo thlen dan leh a inthlahchhawn chhoh dan i han chhui dawn ang hmiang.

Sex chromosomes:

           Red-green colour blindness hi sex-linked inheritance ani a, chuvang chuan sex chromosomes chungchang tawite sawi kai lawk ang. Mihringin chromosomes 46 (23 pair) kan nei a. Chung zinga 44 (22 pair) te chu autosomes an ni a, a bang pahnih (pair khat) te chu sex chromosomes an ti. Sex chromosomes te hi chi hnih an awm a, chungte chu X chromosomes leh Y chromosomes an ti. Mipa ah chuan X leh Y te hi an inkawp a, hetiangin 44 + XY; tin, hmeichhia ah chuan X chromosome pahnih an inkawp ve thung (44 + XX). Chromosome combination ah Y chromosome hi mipana thlentu a ni a, Y chromosome hi a awm lo anih chuan hmeichhia a lo piang thin a, tin, X leh Y comination ah Y aia X a tam zawk chuan a mipana a dal tial tial thin bawk.

Genetics of Red -Green colour blindness:

                Colour hrang hrang kan mitin a thliar hran theihna tur photopigments te hi X chromosome ah a insiam thin a. A siamtu gene te hi a tha lo (defects/mutation) emaw a awm lo (deletion) emaw anih chuan red leh green colour thliar hran theihna a nei dawn lo a ni. Mutation avangin gene tha lo hi a lo awm thin a, tuna kan sawi lai mek he mutation hi sex-linked genes ah anih avangin a inthlahchhawn theih bawk.

Mipa Chromosome          =  44 + XY
Hmeichhe chromosome   =  44 + XX

               A chunga kan hmuh ang hian hmeichhia chuan X chromosome pahnih an nei a, chuvang chuan X chromosome pakhat hian colour blindness siam thei pawh nise, X chromosome dang hi a that tho thin avangin hmeichhia hian colour blindness an nei zen zen lo. Hei hi a chhan ber chu, colour blindness thlen theitu gene tak hi recessive a ni a, pakhat thalo mahse pakhat dang a that chuan a character siam tur kha a siam lo thei thin. Hetiang hmeichhia hian colour blindness an nei lovang a, mahse a rukin an pai thung ang; colour blindness atan carrier an ni a, an fa te ah an thlah chhawng thei thin. Hmeichhia hian colour blindness an nei lo tlangpui a, chutihlaiin hmeichhe colour blindness neih theihna chance chhete chu a awm ve tho mai.

               Mipa ve thung chuan X chromosome pakhat chauh a nei a, chuvangin a X chromosome neih chhunah colour blindness siam thei turin defect a awm anih chuan X chromosome dang, hliahkhuhtu tur a neih ve loh avangin colour blindness a nei ngei ngei dawn tihna a ni thung. Colour blindness hi mipa hrivei bik anih ber mai chu.


Inthlahchhawnna:

            Inthlahchhawnna kawnga chi a lo insiam lai hian mipa chromosome te hi a zatve ah a inthen darh a, 46 chromosomes nei thin kha a chinungte chuan chromosome 23 chauh a lo nei tawh ang a, a thenin 22 + X chromosome an neih laiin a thenin 22 + Y chromosomes an nei ve thung ang. Hmeichhia chuan Y chromosomes an neih ve loh avangin 22 + X chromosomes chauh nei gamete a siam ve thung ang. Chung gametes te inzawm dan azirin hmeichhia emaw mipa emaw an lo piang mai dawn a ni.

Male gamete (22 + Y) fused with  female gamete (22 + X)    =  44 + XY Male.
Male gamete (22 + X) fused with   female gamete (22 + X)   =  44 + XX Female


Heredity of colour blindness:


                  Colour blindness nei te'n an thlah kal zela an thlahchhawn chhoh dan hi chi hnih chi thum lai a awm thei ang a, kan sawi tawh ang khan colour blindness thlentu tak hi X chromosome ah a awm a nih kha. Mipa in colour blindness a nei a, hmeichhia erawh carrier angah a tang thin. Mipa sex chromosomes te leh hmeichhe X chromosome te in fertilize dan hi risk a ni a, a khawi nge in fertilize ang a, nau lo piang tur chu hmeichhia nge a nih anga mipa, colour blind nge a nih ang a, normal nge carrier tih chu vanneih thil liau liau a ni tawh.Combination hrang hrang awm thei zinga a khawi emaw ber chu nau piang tur chuan a nei dawn tihna a nih chu.

                A inthlah chhawn dan chi hrang hrang enchhin ang aw: (Thlalak te hi ka siam an nih hi)

1. Colour blindl male + Normal female:

            Mipa hrisel pangai leh hmeichhia, a ruka colour blindness pai (carrier) an innei anih chuan an kara naute lo piang tur chu mipa pangai a ni thei a, colour blindness nei a ni thei bawk a, tin hmeichhe pangai a ni thei a, carrier colour blindness a ni thei bawk.

Gametes te in zawm (fertilised) dan khi line hmanga thai zawm ka'n tum zet a, mahse a hnawkhnai dawn riauvin ka hria a, tikhian ka dah mawl tawp mai. A hriatthiam theih tho chuan ka hria.


2. Normal male + Carrier female:

             Hmeichhia hi normal anih avangin X chromosome tha pangai chauh a nei dawn a, mipa erawh chuan  colour blindness thlentu X chromosome leh Y chromosome a nei thung. An kara fa lo piang hi hmeichhia anih chuan colourblind carrier a ni ang a, mipa a rawn piang anih chuan colour blindness nei lo a ni thung ang.


3. Colour blind male + Carrier female:

               Colour blindness nei mipa leh carrier hmeichhia an innei anih chuan an fate lo piang chhuak tur chu, mipa pawh, hmeichhia pawh nise, colour blindness an nei vek ang. Mahse hetianga colour blindness nei mipa leh a ruka colour blindness pai (carrier) hmeichhia innei te erawh an vang em em thung. Hei vang hian hmeichhia hian colour blindness an nei zen zen thin lo. A awm erawh an awm ve zauh zauh thin tih chauh a ni.


Tihdam theih a ni em?

              Colour blindness hi thil ho te nia lang si, enge maw hunlai chuan harsatna siamtu ni thei lawi si a ni a. Chuvang chuan tihdam theih anih beiseina a sang em em a. Mahse tun thlengin a tihdam dan tur an la hmuchhuak lo anih hmel. Gene therapy hmang hian tihdam theih mai awm tak chu a ni na a,  zawng (squirrel monkey) a experiment an neih chhinah chuan a hlawhtling ngei mai a, mahse mihringah erawh an la hlawhtling chiah lo anih ka ring. A tihdamna tak tak la hmuchhuak lo pawh nise rawng hmuh theihna lama tanpui theitu tur tarmit leh lens erawh an siam chhuak tho va, hei hian nasatakin a tanpui ngei ang.

             Red-green colour blindness nei te hi mi mipangai, mit khawhmuh fiah tha vek an ni a, rawng hring leh rawng sen an thliar hrang hleithei lo hi an harsatna pakhat a ni a. Chutihlaiin khawpui lianah, traffic road sign red leh green signal an pekna hmunah te chuan motor khalh laiin harsatna an tawk ang tih erawh a hlauhawm. Kan ram ang, khawpui lian te ang ni ve lem lovah chuan driving lamah harsatna a awm chuang lo thung.