Congenital Malformations Registry - Summary Report, 2007

Section 6: Current Topics

1. Case Confirmation and Ascertainment using Cytogenetic Testing Data Obtained from Electronic Clinical Laboratory Reporting System

Background

Hospitals and physicians are required to submit case reports, as well as confirmatory diagnosis information to the New York State Congenital Malformations Registry (CMR) on children who are born or reside in New York State and are diagnosed before the age of two years with major birth defects. However, the majority of the cases with chromosomal anomalies indicated in the hospital discharge files are reported to the CMR without confirmatory testing data, which are usually not available at the time of reporting. The objective of this project was to link the cytogenetic test reports, submitted by cytogenetic testing laboratories via the New York State Department of Health (NYSDOH)'s Electronic Clinical Laboratory Reporting System (ECLRS), to CMR cases to obtain confirmatory diagnoses and identify unreported cases with chromosomal anomalies.

Methods

Cytogenetic testing data submitted by the New York State licensed laboratories and stored on the ECLRS Sybase server were retrieved and matched to CMR cases. Several identifying variables such as the child's name and date of birth and parent's name and address were used in data matching. The laboratory testing results were used to confirm diagnoses of CMR cases for matched reports and to ascertain new birth defects cases by auditing hospitals and physicians using unmatched reports with abnormal testing results.

Results

By the end of 2010, a total of 927 reports on 747 children were submitted to the CMR by 14 cytogenetic testing laboratories via the NYSDOH ECLRS. Among the 747 children reported, 398 (53%) had abnormal test results and 412 (55%) were matched to the CMR cases. From these laboratory reports, 151 new cases with chromosomal anomalies were identified, confirmed and added to the CMR. The additional cases accounted for about 7.8% of all cases with chromosomal anomalies in the CMR for the reporting years 2008-2010.

Conclusions

Cytogenetic laboratory reports can serve as an important source for ascertaining and confirming cases diagnosed with Down syndrome, autosomal deletion syndrome and other chromosomal anomalies. Acquiring molecular genetics testing data directly from cytogenetic testing laboratories enables CMR staff to confirm diagnoses and improve the accuracy and efficiency of case reporting.

2. Linking Children With Congenital Disorders Identified Through Newborn Screening to the Birth Defects Surveillance Program in New York State

Background

The CMR received funds from the U.S. Centers for Disease Control and Prevention in 2008 to develop a population-based surveillance and tracking system in New York State for the long-term follow-up of children identified by the newborn screening program (NBS) through enhanced collaboration between the established NYSDOH newborn screening and birth defects surveillance programs. The objective of the current project was to link children with congenital disorders identified through the NBS program to the CMR to examine their birth defects and identify unreported birth defects cases.

Methods

The NBS Program performs more than 11 million tests annually on approximately 250,000 newborns for more than 40 congenital diseases and the human immunodeficiency virus. Newborns with positive screening results for congenital disorders were obtained from the NBS program for the birth years 2006-2007 and were matched to the CMR database. The Statistical Analysis System (SAS, North Carolina, USA) was used to develop programs for data matching. Deterministic data linkage methods were used with multiple criteria for establishing a match between records using appropriate combinations of personal identifiers. The birth defect information in the CMR for the NBS children identified through data matching were reviewed and analyzed.

Results

A total of 16,781 children with an abnormal screening test were identified from the NBS program for 2006-2007 births. Of these, 1,268 (7.6%) had congenital disorders confirmed by follow-up diagnostic testing. The results from data matching showed that only 35.3% of NBS children with confirmed congenital conditions were matched to the CMR. A majority of the confirmed NBS children were not matched (i.e., not reported) to the CMR. Among the NBS children who had confirmed NBS conditions, 18.8% were found in the CMR having malformations in the cardiovascular or central nervous system. More than 60% of the NBS children with abnormal screening test who were deceased or lost to follow-up or had normal follow-up confirmatory diagnostic tests were found in the CMR having malformations in the cardiovascular or central nervous system.

Conclusions

Linking data from population-based surveillance programs, birth defects registries and newborn screening programs is helpful in understanding the epidemiology of some confirmed screening conditions and associated birth defects, and identifying possible causes of these congenital disorders. The NBS database containing the confirmatory diagnostic testing results can serve as an additional data source for identifying unreported birth defects cases. The project team plans to contact and work with genetic services centers and hospitals to ascertain unreported children with congenital disorders identified through NBS program.

References

Wang Y, Caggana M, Sango-Jordan M, Sun M, Druschel CM. Long-term follow-up of children with confirmed newborn screening disorders using record linkage. Genet Med. 2011;13:881-6.