Wisconsin Newborn Screening Laboratory

Dec 1999 Newsletter: No. 43 Changes

This newsletter is to announce changes in the Wisconsin newborn-screening program beginning shortly after the New Year. These include a switch from Priority Mail to United Parcel Service (UPS) for delivery of newborn screening specimens to the State Laboratory and introduction of new testing. The details are as follows:

United Parcel Service

In May of 1998, the newborn screening program introduced US priority Mail for delivery of newborn screening specimens to the State Laboratory in Madison. Although this resulted in an improvement in the timeliness of samples getting to the screening laboratory (24 hours sooner) and dependability, the improvements didn't meet our expectations. We still are experiencing "lost" samples and actually have seen an increase in specimens damaged during transport due to leaking water samples that are also being sent by Priority Mail. In an attempt to solve these issues, the screening program has decided to the replace Priority Mail with United Parcel Service (UPS). This change is to take place on January 3rd 2000. In preparation for this change UPS will supply you with preaddressed cardboard UPS mailing containers in late December 1999. As with the priority mail envelopes, put all samples that are ready to be sent to the screening laboratory each day in one UPS mailer in time for the UPS pick-up. Most hospitals already have a daily UPS pick up time. Make sure to find out when that time is in your hospital. If your institution doesn't have a routine pick-up time, you can call UPS at 800-742-5877 and ask for an on demand air pickup when the newborn screening samples are ready to be shipped. An additional feature UPS provides is the ability to track specific packages through their system. For example, you will be able to use the Internet to make sure the samples arrived at the State Laboratory of Hygiene. As with the current priority mail, this service is at no cost to you. If you have any questions, please feel free to give the laboratory a call at 608-262-6547.

Expansion of Newborn Screening Testing Update

In our last Newsletter (April 1999) we stated that the Department of Heath and Family Services by their rule making authority added testing for seven Fatty Acid Oxidation (FAO) and seven Organic Acid (AO) disorders. The most frequent disorder of this group is Medium Chain Acyl-CoA Dehyrogenase Deficiency or MCAD. The FAO and OA disorders can be detected in the newborn by measuring the blood acylcarnitine levels by tandem mass spectroscopy (TM/TM). The newborn screening laboratory has acquired the instrumention. Since early summer we have been gaining experience with its operation and detection of these 14 metabolic disorders. This has been more of a challenge than we expected. The identification of these disorders is complex as there is often not a one-to-one correlation between a specific abnormal acylcarnitine level and a particular disorder. With many of the disorders, there are a number of acylcarnitines that are abnormal. Interpretations may also include calculating ratios between various acylcarnitines. Because this technology is new and the fact that we are one of the first screening programs in the country using this particular technology, there is little expertise to tap into. To date we have measured acylcarnitines on over 25,000 newborn screening samples and have identified one case of MCAD and SCAD (Short Chain Acyl-CoA Dehydrogenase Deficiency). We are currently putting the final touches on screening for the FAO and OA disorders that include establishing acylcarnitine normal ranges, developing abnormal reporting processes and reports, notifiying parents, physicians, and hospitals. It is anticipated that routine reporting of these disorders will start within the first couple of months of 2000. A newsletter devoted entirely to screening for the FAO and OA disorders will be sent in early January.

Unidentified Cases:

This year a baby with galactosemia slipped through the newborn screening process without being detected. The abbreviated story goes likes this. The total galactose result was normal at 56 hours of age and the baby was feeding well before sampling. At about three weeks of age the baby was hospitalized and a galactosemia diagnosis was made, after much confusion regarding a significant difference in blood glucose determination made at the bedside (240 mg/dL) and that done in the laboratory (98 mg/dL). The bedside glucose method also reacts to galactose. The State Laboratory re-tested the initial specimen and confirmed the original findings (normal results). The delay in symptomatology is atypical of most galactosemic babies, as they are often very ill within the first week of life. Although the evaluation on this case incomplete, a mild or new genetic mutation is suspected.

Congenital Adrenal Hyperplasia (CAH) was not identified in a baby girl on the initial newborn screen at 26 hours of age. The baby's doctor repeated the newborn screen (in the absence of clinical symptoms) at six days of age and the 17-hydroxprogestone (17-OHP) level was slightly elevated. A third sample at two weeks of age continued to show an increasing 17-OHP and a referral to a pediatric endocrinologist was made. Follow-up testing confirmed a salt losing, life threatening form of CAH. The pediatric endocrinologist subsequently observed mild clitorilmegaly that was not observed by either the obstetrician or the pediatrician.

Please circulate this information to the medical staff of your institution as a reminder that the initial newborn screening tests are not absolute guarantees and that the whole medical team must also rely on clinical judgements.

Remember, any physician or parent (through their physician) in Wisconsin can request a "repeat" newborn screening test on any child at any age. Repeat testing is mandated in some states, it is voluntary (elective) in Wisconsin. We recommend it.

Sampling mix-up possibility:

Twelve newborn screening samples were received on one day from the same hospital; two had similar elevated TSH levels (~105 mIU/mL). Since the frequency of hypothyroidism is about 1 in 4,000 it seemed unlikely that two hypothyroid cases would be born in the same hospital at the same time. Confirmatory testing indicated that one of the babies was indeed hypothyroid and the second was normal. This was the first time a baby with a TSH level that high (>100 mIU/mL) was not confirmed to have hypothyroidism in the 20+ years of screening for the disorder. Although the possibility that the hypothyroid baby may have been drawn twice and a second, probably "normal" baby not drawn was never absolutely confirmed, it is very likely that this is what happened. Please review the newborn screening sample collection processes in your institution. Be certain that there are no "gaps" where there could be confusion as to which babies have or have not been drawn.

Follow-Up testing:

A baby with sickle-hemoglobin C disease was detected on newborn screening. The confirmatory testing on whole blood at a month of age was done in a reference laboratory instead of the newborn screening laboratory as recommended. The reference laboratory identified and reported four hemoglobins (Fetal, adult, sickle and hemoglobin C), a physiological impossibility. Also the interpretation of the findings was confusing in that both sickle and hemoglobin C trait was reported has well as a compound heterozygote for "S" and "C" hemoglobin and hereditary persistent fetal hemoglobin. It is obvious that the reference laboratory was inexperienced with testing newborn babies for hemoglobins.

Y2K

The newborn screening laboratory testing processes are Y2K compliant and should the power grid fail (locally or regionally) a contingency plan is in place so that the critical testing, Congenital Adrenal Hyperplasia, Galactosemia, Phenylkentonuria, will be completed on emergency generated power if needed. Of course there could be reporting delays of normal results should a significant power failure occur. Abnormal results would be delivered to the babies physician by what ever means it takes; phone or personal contact if need be. We as a laboratory are working with state emergency government and are prepared to deal with any acute communication needs.

We hope this information about your 1999 Newborn Screening was interesting and useful. Your continued support and personnel efforts truly makes newborn screening in Wisconsin a showcase in the nation. As we close one millennium and start another we look forward to working with you to continue to provide all children born in Wisconsin the best quality of life possible.

Happy Holidays and GO BADGERS.

Sincerely,