MECP2 and Down syndrome: For the recurrent microdeletion or microduplication syndromes, the most common pathogenic CNVs were 15q11.2-q13.1 deletion (#105830 or #176270, 5 cases), 7q11.23 deletion (#194050, 4 cases), MECP2 duplication/deletion (#300260 or #312750, 4 cases), 16p11.2 deletion (#611913 or #613444, 3 cases), 22q11.21 deletion (#188400, 2 cases), 5p− (#123450, 2 cases), 1p36 deletion syndrome (#607872, 2 cases), and 1q43-q44 deletion syndrome (#612337, 2 cases).