Achromatopsia, wanda kuma ake kira achromatia, wani yanayi ne da ba kasafai ba na ido wanda ke hana ku ganin launuka. Yana da asalin kwayoyin halitta a mafi yawan lokuta, amma kuma yana iya haifar da lalacewar kwakwalwa. Marasa lafiya da abin ya shafa suna ganin duniya a baki da fari.

Achromatopsia yana nufin rashin iyawar mutum don ganin launuka. Akwai nau'o'i da yawa:

Cikakken achromatopsia na haihuwa

Sakamakon maye gurbin kwayoyin halitta a daya ko fiye da kwayoyin halitta da ke da hannu a hangen launi, retina da ke layi a bayan ido ba shi da abin da ake kira "mazugi" photoreceptor cell wanda ke bambanta launuka da cikakkun bayanai a cikin haske. Sakamakon: marasa lafiya da abin ya shafa suna gani a cikin inuwar launin toka. 

Bugu da ƙari, suna da babban hankali ga haske da ƙananan ƙarancin gani. Duk wannan daga haihuwa. Wannan makantar kalar da ake danganta ta da kwayoyin halitta, ya shafi mutanen da iyayensu biyu masu dauke da maye gurbi iri daya ne kuma suka yada zuwa gare shi. Wannan shine dalilin da ya sa yaduwarsa ba ta da yawa, na adadin 1 a cikin 30 zuwa 000 na haihuwa a duniya;

Achromatopsia na ɗan lokaci ko rashin cikawa

Wannan nau'i kuma na kwayoyin halitta ne, amma, ba kamar na farko ba, yana da alaƙa da maye gurbi a kan X chromosome kuma baya rinjayar duk cones na retina. Ya bar wadanda m zuwa blue. Wannan shine dalilin da ya sa kuma ana kiran wannan Pathology "blue cone monochromatism". 

Marasa lafiya tare da shi ba sa ganin ja da kore, amma suna ganin shuɗi. Saboda rashin isassun isassun mazugi, kyawun ganinsu duk da haka yana da rauni sosai kuma ba za su iya jurewa haske ba. Tun da rashin cikar achromatopsia yana da alaƙa da maye gurbi mai alaƙa da chromosome na X, galibi yana shafar yara maza, waɗanda ke da kwafin wannan chromosome guda ɗaya (biyu na 23 na chromosomes ɗin su na X da Y). Tun da yake 'yan mata suna da nau'in chromosomes guda biyu na X, dole ne su gaji maye gurbi daga iyayen biyu don zama achromat, wanda ya fi wuya;

Cerebral achromatopsia 

Ba daga asali ba ne. Yana bayyana biyo bayan raunin kwakwalwa ko hatsarin cerebrovascular (bugun jini) wanda ya shafi cortex na gani. Marasa lafiya waɗanda retina ta al'ada ce kuma waɗanda suka ga launuka sosai har zuwa wannan lokacin sun rasa wannan ikon ko dai gaba ɗaya ko kaɗan. Kwakwalwarsu ba za ta iya sarrafa irin wannan bayanin ba.

Achromatopsia na haihuwa cuta ce ta kwayoyin halitta. Ana iya haɗa kwayoyin halitta da yawa: 

• GNAT2 (chromosome 1);
• CNGA3 (chromosome 2);
• CNGB3 (chromosome 8);
• PDE6C (chromosome 10);
• PDE6H (chromosome 12);
• kuma, a cikin yanayin monochromatism blue mazugi, OPN1LW da OPN1MW (X chromosome). 

Yayin da achromatopsia na haihuwa yana bayyana kansa tun daga haihuwa, akwai wasu lokuta na achromatopsia da aka samu. Suna lalacewa ta hanyar lalacewa ta kwakwalwa: rauni ko bugun jini da ke shafar cortex na gani.

A cikin marasa lafiya tare da maye gurbi a cikin ɗaya ko fiye na waɗannan kwayoyin halitta, retina ba ta da cones wanda ke ba mu damar ganin launuka da cikakkun bayanai. Suna da sel kawai a cikin "sanduna", alhakin maimakon hangen nesa na dare, a cikin inuwar launin toka.

Achromatopsia na haihuwa yana da alaƙa da:

• makantaccen launi : wannan shi ne duka a cikin cikakkun achromat, waɗanda suke ganin duniya a baki da fari, ko kuma kusan duka a cikin monochromat, wanda har yanzu yana iya bambanta blue;
• muhimmanci photophobia, wato, hypersensitivity zuwa haske;
• rage girman gani, tsakanin 1/10 da 2/10;
• un nystagmus, ma'ana, ba da son rai, jujjuyawar motsin ido na ido, musamman a gaban haske mai haske. Wannan alamar na iya shuɗewa tare da shekaru;
• petit scotome shuka, wato, ɗaya ko fiye ƙananan tabo a tsakiyar filin gani.

Wannan rashi yana samuwa tun suna karami, amma kyama ga haske da kuma matsananciyar motsin idon jarirai ne ke fara fadakar da iyaye musamman idan akwai wasu matsaloli a cikin iyali. Lokacin da yaron ya isa ya bayyana kansa, ana iya yin gwajin launi amma bai isa ba, tun da wasu monochromat suna iya daidaitawa, har zuwa suna iya suna wasu launuka. Electroretinogram (ERG) kawai, yana auna aikin lantarki na masu ɗaukar hoto a cikin retina, zai iya tabbatar da ganewar asali. Binciken kwayoyin halitta sannan ya ba da damar tantance maye gurbin da ake magana akai.

Nahaihu achromatopsia ne barga Pathology. Duk da haka, ci gaba da lalacewa na macula, wato, yankin da ke tsakiyar retina, na iya bayyana a wasu marasa lafiya, musamman ma lokacin da suka tsufa. 

Cerebral achromatopsia shine kawai asarar hangen nesa na launi kwatsam bayan raunin kai ko bugun jini. 

A halin yanzu babu magani ga wannan Pathology, kawai mafita don sauƙaƙa alamun. Kiyayya ga haske da kuma hankali ga bambance-bambance musamman ana iya inganta ta ta hanyar saka tabarau ko ruwan tabarau masu launin ja ko launin ruwan kasa, wanda aka sani da “chromogenic”. Gilashin haɓakawa a babban haɓakawa na iya sauƙaƙa karantawa. Har ila yau, akwai wasu kayan taimako don haɓaka yancin kai na haƙuri: horarwa a cikin locomotion, daidaita lokacin yin jarrabawar jami'a, da dai sauransu.

Ee. Kamar yadda achromatopsia cuta ce ta nakasar kwayoyin halitta, ana iya ba da ganewar asali na haihuwa ga ma'auratan da ke cikin haɗari, wato ma'auratan da duka abokan haɗin gwiwa ke haifar da maye gurbin da ke da alaƙa da wannan ilimin cututtuka. Idan maye gurbi iri ɗaya ne, suna da damar 25% na haihuwar ɗan achromatic.

A cikin yanayin monochromatism, uwa ce kawai ke iya watsa ƙarancin ƙwayar cuta ga zuriyarta. Idan yaro ne, zai zama achromatic. Idan mace ce, za ta zama mai ɗaukar maye gurbin, kamar mahaifiyarta.