Gene Location

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Disease Name 
SHORT-CHAIN ACYL-COA DEHYDROGENASE DEFICIENCY (SCADD) 
(ACADS DEFICIENCY; SCADH DEFICIENCY; SCAD DEFICIENCY) 
Classification:  Fatty acid oxidation defect 
Genetic Information 
Inheritance:  Autosomal Recessive. 
Population 
Incidence: 
1:40,000-1:100,000 
 
Ethnic Incidence:   No known population at increased risk. 
Gene & Location:  ACADS, SCAD- 12q22-qter 
Common 
Mutation: 
No common disease mutations have been identified.  Two common SCAD 
“disease susceptibility” mutations (625G>A) (511C>T) are present in 14 percent 
of the general population. 69 percent of persons with ethylmalonic aciduria are 
either heterozygous or homozygous for these susceptibility mutations. 
OMIM #  *606885; #201470 
Disease Information 
Symptom Onset:  Only 20 SCAD deficient patients have been described. The majority became 
symptomatic in the first week to three months of life, four before 24 months and 
two presented as adults. 
Symptoms:  About 50 percent of patients have hypotonia and developmental delay.  Variable 
symptoms are present in patients presenting early, including seizures, respiratory 
distress, acidosis, poor feeding, vomiting or failure to thrive, and one death. Only 
one patient had hypoglycemia. Acute symptoms in most patients did not recur. 
Both adults presented with proximal muscle weakness associated with periods of 
pain, nausea/vomiting and shortness of breath. 
Physical Findings:  No specific dysmorphology. 
Treatment:  Supportive standard treatment of symptoms. Common fatty acid oxidation 
therapies including low fat diet, carnitine and riboflavin supplements have not 
improved hypotonia or developmental delay. One patient with cyclic vomiting 
improved on frequent feeding. 
Natural History 
without 
treatment: 
Highly variable, from death in the neonatal period to probable asymptomatic 
persons. It is reassuring that some of the early onset patients completely 
recovered and have had normal growth and development into adulthood. Long-
term outcome beyond adolescence is unknown, specifically the development of 
further muscle weakness.  Environmental stressors are suspected to precipitate 
symptoms in some cases, but they are not well understood. 
Natural History 
with treatment: 
There is no proven efficacy of the usual treatments for fatty acid oxidation 
disorders, with the possible exception of avoiding fasting. 
Metabolic Information 
Missing Enzyme 
& Location: 
Short chain acyl-CoA dehydrogenase, liver, muscle and fibroblasts. SCAD is one 
of three enzymes that catalyze the last step in mitochondrial beta-oxidation of 
fatty acids. 
MS/MS profile:  C4 (butyryl/ isobutyryl carnitine)- elevated. 
C4/C2- elevated. 
C4/C3- elevated. 
Prenatal testing:  If both gene mutations are known theoretically possible. 
Miscellaneous 
Information: 
Ethylmalonic acid and methylsuccinate are elevated in the urine. Maternal 
pregnancy complications include HELLP or acute fatty liver of pregnancy 
(AFLP) with some affected SCAD fetuses.  
Some patients will have isolated excretion of C4 and ethylmalonic acid 
Credit:  Prepared by the North West Regional Newborn Screening Program Judith 
Tuerck, RN, MS, and Lorinda Paradise at Oregon Health Services University in 
Portland, Oregon and by Sara Copeland MD, Iowa Neonatal Metabolic 
Screening Program. 
Sites of Reference:  NORD - Short Chain Acyl CoA Dehydrogenase Deficiency (SCAD) 
www.rarediseases.org/search/rdbdetail_abstract.html?disname=Short%20Chain 
%20Acyl%20CoA%20Dehydrogenase%20Deficiency%20%28SCAD%29 
 
Save Babies Through Screening Foundation, Inc  
Short Chain Acyl-CoA Dehydrogenase Deficiency (SCAD) 
http://www.savebabies.org/diseasedescriptions/scad.php 
 
OMIM - Short-Chain Acyl-CoA Dehydrogenase Deficiency (SCAD) 
www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?201470 
Support Groups:  FOD Family Support Group 
805 Montrose Drive 
Greensboro, NC 24710 
www.fodsupport.org/ 
Contact: Deb Lee Gould 
(336) 547-8682 
FODgroup@aol.com 
 
United Mitochondrial Disease 
Foundation 
P.O. Box 1151 
Monroeville, PA 15146-1151 
www.umdf.org/ 
(412) 793-8077 
info@umdf.org 
James William Lazzaro Foundation 
4493 Liberty Road 
South Euclid, OH 44121 
www.jwlsite.com/ 
Contact: Jamie Lazzaro 
(502) 254-2209 
info@jwlsite.com 
 
Children Living with Inherited 
Metabolic Diseases (CLIMB)  
Climb Building  
176 Nantwich Road  
Crewe, CW2 6BG  
United Kingdom  
(+44) 0870 7700 326  
Fax: (+44) 0870 7700 327  
steve@climb.org.uk  
www.climb.org.uk 
 

Natural History

http://www.idph.state.ia.us/genetics/common/pdf/scad.pdf

Natural History

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