NOTCH2NL Copy Number (IMAGE) Howard Hughes Medical Institute Caption On the long arm of chromosome 1, deleting a copy of the gene NOTCH2NL (green), can result in microcephaly, or abnormally small brain size (left). Duplicating these genes can have the reverse effect: macrocephaly, or oversized brains (right). Credit I. Fiddes et al./Cell 2018 Usage Restrictions Use with credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.