Articles on adoption, foster care, & pediatrics

long line 800 144dpi.jpg

Newborn Screening Tests

In the US, newborns are tested for congenital disorders of metabolism and a growing list of other conditions by heelstick screening tests. What gets tested by these newborn screening panels is decided by individual states. As a result, there is a substantial variability among state panels. As of April, every state screens for PKU (phenylketonuria), galactosemia and congenital hypothyroidism. Twelve states currently mandate screening for over 40 disorders. These states are able to screen for this high number of disorders with the use of tandem mass spectrometry, which is a technology that analyzes the metabolite composition of the blood spots.

These are all rare disorders: the most common is congenital hypothyroidism (prevalence is about 1 in 3,500), with the rarest being homocystinuria and MSUD (prevalence for is about 1 in 200,000 for each). But intervening early can improve outcomes in many cases, so there is an push to test for more and more conditions.

In terms of drawbacks, the test itself is a simple heelstick. There is additional cost involved in expanded screening, however. Most importantly, as with any screening test, these screens are designed to err on the side of overdiagnosis, so confirmatory tests may be necessary, and "false positives" can certainly cause a lot of stress.

If interested, you can obtain kits for expanded newborn screening for rare inherited disorders through one of these companies:

These services screen for anywhere from 20-50 disorders and the cost ranges from $35 – $89 (plus shipping and handling). Many require the involvement of a physician in the ordering and interpretation. Not all are set up for older/international screening situations. Pediatrix seems to be the only one of these to offer a comprehensive panel that also includes the standard state screens. Unfortunately, since these are newborn screening kits, they are not designed for older infants and toddlers. You'll want to check with the company to see what their age limits are for various tests ...

In the international adoption scenario, provided the child's current legal guardian is OK with testing (a big and usually insurmountable if in most instances, but preadoptive parents in Guatemala have been successful with this), you'll need to be sure that the kit you use also covers the basic newborn screen, and not just tests that are designed to supplement the common state screens. In Korea, they do routinely test for PKU and hypothyroidism. Russia also reportedly tests for these in many regions, but the results are not typically available.

In our clinic we do not routinely send newborn screening tests on international adoptees. The Washington State lab is not set up to run the most important screens on older infants and toddlers. With our initial bloodwork, we do screen for various types of anemia, which should uncover clinically significant hemoglobin disorders, and we also screen for hypothyroidism. If children have symptoms of metabolic illnesses, there are blood and urine tests that we can perform as well.

Other Newborn Screening Resources:

Thanks to Beth Tarini, MD for background material

Café-au-lait Spots and Neurofibromatosis

There is a group of genetic neurologic conditions called neurocutaneous syndromes where skin findings can be the first clue to a broader syndrome. One of the most common is neurofibromatosis type 1 (NF1), which occurs in up to 1 in 3000 individuals. This is a condition where benign tumors grow on nerve tissue, causing skin, bone, and sometimes brain issues.

One of the first signs of NF1 can be "café-au-lait spots", which are typically light to dark-brown flat, discrete, round or oval skin patches. These spots become more common with age, and can be more common in African-Americans, but most of us have 3 or less. If more than 5 café-au-lait spots (>5mm each) are seen, this should be considered NF1 until proven otherwise. Other findings like freckling in the armpits or groin, or firm, rubbery neurofibromas typically show up later, in preadolescence. Many with NF1 only develop a few fibromas, but they can be quite cosmetically significant for some.

Mental retardation is rare with NF1, but attentional and specific learning issues are common in this disorder. While fibromas are benign, there is a somewhat increased risk of malignancy (3-5%), and brain fibromas can be associated with epilepsy. Short stature and large head are common in NF1.

The majority of folks with NF1 have mild disease, and complications are often correctable to some degree. Treatment focusses on surgery for painful or cosmetically significant fibromas, and addressing learning issues through early intervention and school supports.

Here are the diagnostic criteria for NF1 (2 or more are required for the diagnosis), from GeneReviews:

  • Six or more café au lait macules over 5 mm in greatest diameter in prepubertal individuals and over 15 mm in greatest diameter in postpubertal individuals
  • Two or more neurofibromas of any type or one plexiform neurofibroma
  • Freckling in the axillary or inguinal regions
  • Optic glioma (tumor of the optic pathway)
  • Two or more Lisch nodules (iris hamartomas)
  • A distinctive osseous lesion such as sphenoid dysplasia or thinning of long bone cortex with or without pseudarthrosis (related orthopedic issues)
  • A first-degree relative (parent, sib, or offspring) with NF1 as defined by the above criteria

Additional Resources: