Pediatric emergency medicine trisk 2421 2421
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (118.94 KB, 1 trang )
TABLE 95.2
CLINICAL AND LABORATORY FINDINGS OF INBORN ERRORS OF METABOLISM
Most IEMs are autosomal recessive in their inheritance, but they may be X-linked, mitochondrial, or,
uncommonly, autosomal dominant. A family history of either known metabolic disease or unusual
medical presentations (e.g., death due to neurologic, cardiac, and/or hepatic dysfunction; sepsis; or
unexplained neonatal or sudden infant deaths in siblings or maternal male relatives) should increase
suspicion for an underlying metabolic disease. Maternal illness during pregnancy, particularly acute fatty
liver of pregnancy or HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome, may be due to
maternal heterozygosity for a fatty acid oxidation defect, specifically 3-hydroxyacyl-CoA dehydrogenase
deficiency. A negative family history and negative NBS do not rule out an IEM. It is important to note
that NBS varies from state-to-state and not all IEMs are part of the screen. For example, several urea
cycle disorders (ornithine transcarbamylase deficiency and carbamoyl phosphate synthetase deficiency)
are not detectable by NBS. It is also worth keeping in mind that the results of the NBS are often not
available in the first several days of life.
Neonate (<30 days of life). Most of the IEMs that are acutely life threatening during the neonatal
period usually present as acute encephalopathy and/or hepatic disease. Among the most common lifethreatening IEMs to present in the neonate are amino acid disorders, organic acidemias, urea cycle
defects, galactosemia, and hereditary fructose intolerance. Manifestations may include poor feeding,
vomiting, diarrhea, dehydration, temperature instability, tachypnea or apnea, cyanosis, respiratory failure,
bradycardia, poor perfusion, hiccups, jaundice, hepatomegaly, pseudoobstruction, irritability, lethargy,
coma, seizures, involuntary movements (e.g., tremors, myoclonic jerks, boxing, pedaling), posturing
(e.g., opisthotonus), and abnormal tone (e.g., hypertonia or central hypotonia). These same symptoms are
seen in an infant with sepsis, congenital viral infections, respiratory illness, cardiac disease,
gastrointestinal obstruction, hepatic dysfunction, renal disease, central nervous system (CNS) problems,
and drug withdrawal. It is worth noting that term infants who develop symptoms of sepsis without known
