Health Professionals Guide to Newborn Screening

Organic Acidemia Disorders

Organic Acidemias (OA) are a class of inherited metabolic disorders that lead to accumulation of organic acids in biological fluids (blood and urine). This, in turn, produces disturbances in the acid-base balance and causes alterations in pathways of intermediary metabolism. Clinical symptoms of OA disorders may include vomiting, metabolic acidosis, ketosis, dehydration or coma, hyperammonemia, lactic acidosis, hypoglycemia, failure to thrive, hypotonia, global developmental delay, sepsis and hematological disorders.

Analyte Measured:

Acylcarnitine profiling by Tandem Mass Spectrometry

Disorders Reported, Reporting Ranges and Prevalence:

Disorder Abbrev. Abnormal Acylcarnitine(s) uM  Prevalence (estimated) Glutaryl CoA Dehydrogenase Deficiency Type I GA-I GA1  C5DC ≥0.10 1:92,000 Propionyl CoA Carboxylase Deficiency PA  C3≥ 6.92 C3/C2≥0.20 1:150,000 Methylmalonic Acidemia: mutase Clb A & B Clb C & D MMA C3 ≥ 6.92 C3/C2 ≥ 0.30   1:46,000* Isovaleryl CoA Dehydrogenase Deficiency 2-Methylbutyryl CoA dehydrogenase Deficiency IVA 2MBCD C5 ≥ 0.44 C5/C3 ≥ 0.50 C5/C2 ≥ 0.05 1:92,000 1:13,000 3-Methylcrontonyl CoA Carboxylase Deficiency 3-MMC C5OH ≥ 0.60 1:29,000 Mitochondrial Acetoacetyl CoA Thiolase Deficiency 2-Methyl-3-Hydroxbutyryl CoA Dehydrogenase b-KT MHBD C5:1 ≥ 0.13 C5OH ≥ 0.60 1:460,000 Unknown 3-Hydroxy-3-Methylglutaryl-CoA Lyase Deficiency HMG C5OH ≥ 0.60 C6DC ≥ 0.20 Unknown Multiple CoA Carboxylase Deficiency MCD C5OH ≥ 0.60 C3 ≥ 6.92 Unknown Isobutyryl CoA Dehydrogense Deficiency IBD C4 ≥ 1.20 Unknown 3 Methylglutaconyl CoA Hydrastase Deficiency 3MGA C6DC ≥ 0.20 Unknown * Includes benign and mild cases

Feeding Effect:	None
Timing Effect:	Early specimen collections may enhance the detection of these disorders.
Confirmation:	Referral to metabolic center for urine organic acids analysis, specific enzyme analysis and/or mutation analysis.
Treatment:	Low protein diet, carnitine or vitamin supplements, avoid fasting

Information on treatment centers is also available on this site.

For information about other screened disorders, click on the next page button, or follow one of these links:

• Argininosuccinic Acidemia (ASA)	• Hemoglobin Variants
• Biotinidase Deficiency	• Homocystinuria
• Congenital Adrenal Hyperplasia	• Hypermethioninemia
• Congenital Hypothyroidism	• Hyperphenyalaninemia
• Citrullinemia (Types I & II)	• Maple Syrup Urine Disease
• Cystic Fibrosis	• Organic Acidemias (14)
• Fatty Acid Oxidation Disorders (12)	• Phenylketonuria (Includes Biopterin Cofactor defects of regeneration and biosynthesis)
• Galactosemia	• Severe Combined Immune Deficiency (SCID)
• Hemoglobin S-Beta Thallassemia	• Sickle Cell Disease
• Hemoglobin S/C Disease	• Tyrosinemia (Types I,II, & III)

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