bengaluru in what could be the largest improvement to the human reference genome since its initial release 20 years ago researchers from telomeretotelomere t2t consortium an international collaboration of around 30 institutions have sequenced the first truly complete human reference genomethis could mark a new era of genomics where no region of the genome the entire human genetic code is beyond reach this unlocks newer regions in human dna and holds potential to enhance understanding of a wide variety of disorders affecting people it could also lead to better genetic screening that enables quick and specific diagnostic tests to treat various maladies toi accessed the preprint paper titled the complete sequence of a human genome which dubs the new sequence t2tchm13 final validation of this was also aided by software from chirag jain assistant professor department of computational and data sciences the indian institute of science iiscgap fillingin 2001 celera genomics and international human genome sequencing published the first drafts of the human genome and revolutionised genomics but there were gaps as per nature sequencing was not truly complete and about 15 was missing owing to technological limitations subsequently scientists solved some puzzles but the most recent human genome which geneticists have used as a reference since 2013 still lacked 8 of the full sequencenow researchers at the telomeretotelomere t2t consortium an international collaboration of around 30 institutions across the world have sequenced the first truly complete human reference genome toi accessed the preprint paper titled the complete sequence of a human genome which dubs the new sequence t2tchm13human genome is the complete set of the dna dna strands are like a fourletter language four chemical units or bases that are the alphabet the letters combine specifically with letters in the opposite strand to form words base pairs or bp encoding information all these words are stored in chromosomes in human cellsif a human genome were a history book it would have around 3billion words bp across 22 chapters chromosomes giving information on human journey through time with a detailed blueprint for building every human cell that would give health care providers new powers to treat prevent and cure diseases so if 8 of the genome was not sequenced earlier it meant some pages of this book were missing that means not all of the 3 billion base pairs that each human genome contains was sequenced addressing this 8 gap t2t has completed the first truly complete sequence of a human genome the paper readsthe sequence reference includes gapless assemblies for all 22 autosomes plus chromosome x which look same in females and males corrects errors introduces 200 million bp of novel sequence containing 2226 gene copies 115 are predicted to be protein coding important to understand diseases newly completed regions include all centromeric satellite arrays and the short arms of all five acrocentric chromosomes satellite arrays known to vary extensively in the human population will aid medical genomics and thereby give better understanding