Background: A rare disease is any disease that affects a small part of the population. All chromosomal diseases accompany a person throughout life, even if the symptoms do not appear immediately. Many chromosomal abnormalities appear early in life. Thirty per cent of children with rare diseases will die before their fifth birthday. The prevalence of rare diseases may vary between populations, so a disease that is missed in some populations may be common in others. Prevalence, by definition, ranges from 1/1,000 to 1/20,000. Objective: To report the incidence of chromosome abnormalities after establishing a Birth Defects Integrated Center and birth defects surveillance at Harapan Kita NWCHC. Method: Data were collected retrospectively from a cytogenetic laboratory, Harapan Kita NWCHC, between 2010 and 2021. Inclusion criteria were peripheral blood samples sent to the cytogenetic laboratory. Culture failure samples were excluded. Result:  We obtained samples from infants in 1042 with clinical suspicion of genetic abnormalities, 98% of whom were successful for analysis. 183 of 392 inborn infants were diagnosed as abnormal, whereas in the group of referred outpatients, 381 of 650 abnormalities were found. In 9% of the cases, a rare chromosomal abnormality was found. Conclusion: It is advisable to perform on an infant with suspected chromosomal abnormalities chromosomal investigations.