Case3: Newborn, Hmong (China)

CasePresentingHPOs:

HPOFreeText: Born after normal pregnancy, postnatal course normal except for moderately elevated C5-acylcarnitine found during NBS. Treatment with L-carnitine supplementation.

CaseNotHPOs:

CasePreviousTesting: Urine 2-MBG 55.7 ug/mg creatinine (ref 0.3-7.5); urine IVG 1.2 ug/mg creatinine (ref 0.3-14.3).

CaseGenotypingMethod: PCR and sequencing of entire gene.

Variant: NM_001609.3:c.1165A>G (p.Met389Val) (homozygous)

CAID: CA5730948

gnomAD: East Asian 0.0005513

VariantEvidence: PCR of cDNA using primers in exon 9 and exon 11 showed that exon 10 was missing. Analysis of intron exon junctions flanking exon 10 did not reveal any changes.

CaseAddInfo: Diagnosis confirmed by Western blot of fibroblasts which showed no SBCAD protein.

CasePMIDs:

Case1: Newborn, male, Hmong (China)

CasePresentingHPOs:

HPOFreeText: Delivered at 33 weeks of gestation as a result of preterm labor. Postnatally required care for respiratory distress and pneumonia. NBS revealed elevated C5 acylcarnitine. Treated with L-carnitine supplementation and discharged at 4 weeks. Normal development at 12 months.

CaseNotHPOs:

CasePreviousTesting: Plasma C5-acylcarnitine 0.7, 3.4 umol/L (ref <0.6); urine 2-MBG 1.8, 10.2, 13.4, 28.7 ug/mg creatinine (ref 0.3-7.5); urine IVG 0.1, 0.3, 0.4, 1.1 ug/mg creatinine (ref 0.3-14.3).

CaseGenotypingMethod: PCR and sequencing of entire gene.

Variant: NM_001609.3:c.1165A>G (p.Met389Val) (homozygous)

CAID: CA5730948

gnomAD: East Asian 0.0005513

VariantEvidence: PCR of cDNA using primers in exon 9 and exon 11 showed that exon 10 was missing. Analysis of intron exon junctions flanking exon 10 did not reveal any changes.

CaseAddInfo: Diagnosis confirmed by Western blot of fibroblasts which showed no SBCAD protein. Treatment discontinued without consequence.

CasePMIDs:

PMID: 12837870

Gene: ACADSB

Disease: 2-methylbutyrylglycinuria

MonDO: MONDO:0012392

InheritancePattern: AR

Case2: Newborn, Hmong (China)

CasePresentingHPOs:

HPOFreeText: Born after normal pregnancy, postnatal course normal except for moderately elevated C5-acylcarnitine found during NBS. Treatment with L-carnitine supplementation. Treatment was discontinued without consequence.

CaseNotHPOs:

CasePreviousTesting: Plasma C5-acylcarnitine 3.0, 3.2 umol/L (ref <0.6); urine 2-MBG 2.9, 15.5 ug/mg creatinine (ref 0.3-7.5); urine IVG 0.1, 0.6 ug/mg creatinine (ref 0.3-14.3).

CaseGenotypingMethod: PCR and sequencing of entire gene.

Variant: NM_001609.3:c.1165A>G (p.Met389Val) (homozygous)

CAID: CA5730948

gnomAD: East Asian 0.0005513

VariantEvidence: PCR of cDNA using primers in exon 9 and exon 11 showed that exon 10 was missing. Analysis of intron exon junctions flanking exon 10 did not reveal any changes.

CaseAddInfo: Diagnosis confirmed by Western blot of fibroblasts which showed no SBCAD protein.

CasePMIDs:

PMID: 17945527

Gene: ACADSB

Disease: 2-methylbutyrylglycinuria

MonDO: MONDO:0012392

InheritancePattern: AR

Case1: male, German, 4 days (onset)

CasePresentingHPOs:

HPOFreeText: Neonatal screening suggestive of MBD deficiency. Treatment since 9 months with 90 mg L-carnitine per kg body weight. Normal at 6 years old.

CaseNotHPOs:

CasePreviousTesting: Day 4: elevated C5 acylcarnitine (0.57 umol/l, ref <0.31) confirmed by 3 of 4 subsequent tests of DBS. Urinary organic acids showed normal N-isovalerylglycine but increased N-methylbutyrylglycine.

CaseGenotypingMethod: Genomic DNA extracted from DBS or peripheral blood. All exons and intron-exon boundaries of ACADSB sequenced.

Variant: NM_001609.3(ACADSB):c.38G>A (p.Arg13Lys) (homozygous)

ClinVar: 299068

gnomAD: European (Finnish): 0.4494; 1546 homozygotes

VariantEvidence: High frequency, listed as benign in ClinVar.

CaseAddInfo:

CasePMIDs:

Case5: male, Lebanon, neonatal screening 7 days

CasePresentingHPOs: HP:0045045, HP:0002155

HPOFreeText: Neonatal screening suggestive of MBD deficiency. Treatment of 150-200 mg L-carnitine/kg body weight and has shown normal development until 10 months.8 months: elevated serum triglycerides and GOT.

CaseNotHPOs:

CasePreviousTesting: Neonatal screening: elevated C5 acylcarnitine (0.51 umol/l and 0.72 umol/l; upper 99th percentile 0.29 umol/l) and C5/C2 acylcarnitine ratio (0.04 and 0.06; upper 99th percentile 0.02). 8 months: elevated serum triglycerides (673 mg/dl; ref <205) and GOT (57 U/l; ref <35).

CaseGenotypingMethod: Genomic DNA extracted from DBS or peripheral blood. All exons and intron-exon boundaries of ACADSB sequenced. Sibling and parents: only exons 1, 4, and 10 were analyzed.

Variant: 1. NM_001609.3(ACADSB):c.1159G>A (p.Glu387Lys) 2. NM_001609.3(ACADSB):c.443C>T (p.Thr148Ile)

ClinVar: 1. 9203; 2. 9202

gnomAD: 1. Latino 0.0004797, Overall 0.0002404, no homozygotes; 2. South Asian 0.002678; Overall 0.0008097, no homozygotes

VariantEvidence: In vitro expression of c.1159G>A in E. coli shows no protein on Western blot, reduced enzymatic activity to 2% and defects in protein folding and stability. c. 443C>T decreases ACADSB enzymatic activity to 2.8% of wild type in vitro (PMID: 20547083).

CaseAddInfo: 3 year old brother had a similar metabolite profile, but was not picked up by newborn screening (different cut-off values were used). Parents were normal. Patient also had c.38G>A polymorphism.

CasePMIDs:

Case2: female, Turkish, neonatal screening

CasePresentingHPOs: HP:0000403

HPOFreeText: Neonatal screening suggestive of MBD deficiency. Normal free carnitine. No treatment, but normal at 6 years. Adenotomy and bilateral paracentesis at 5.5 years.

CaseNotHPOs:

CasePreviousTesting: Neonatal screening: elevated C5 acylcarnitine (0.75 umol/l, ref <0.31). Urinary organic acids showed increased N-methylbutyrylglycine.

CaseGenotypingMethod: Genomic DNA extracted from DBS or peripheral blood. All exons and intron-exon boundaries of ACADSB sequenced.

Variant: NM_001609.3(ACADSB):c.443C>T (p.Thr148Ile) (homozygous)

ClinVar: 9202

gnomAD: South Asian 0.002678; Overall 0.0008097, no homozygotes

VariantEvidence: Decreases ACADSB enzymatic activity to 2.8% of wild type in vitro (PMID: 20547083).

CaseAddInfo: Consanguinity. 7 year old brother also found to have enzyme deficiency. No symptoms.

CasePMIDs:

Case4: female, Turkish, neonatal screening

CasePresentingHPOs:

HPOFreeText: Neonatal screening suggestive of MBD deficiency. Treatment of 100 mg L-carnitine/kg body weight and has shown normal development until 3 years.

CaseNotHPOs:

CasePreviousTesting: Neonatal screening: elevated C5 acylcarnitine (0.68 umol/l and 2.08 umol/l , ref <0.31). Urinary organic acids showed increased N-methylbutyrylglycine.

CaseGenotypingMethod: Genomic DNA extracted from DBS or peripheral blood. All exons and intron-exon boundaries of ACADSB sequenced.

Variant: NM_001609.3(ACADSB):c.1159G>A (p.Glu387Lys) (homozygous)

ClinVar: 9203

gnomAD: Latino 0.0004797, Overall 0.0002404, no homozygotes

VariantEvidence: In vitro expression in E. coli shows no protein on Western blot, reduced enzymatic activity to 2% and defects in protein folding and stability (PMID: 20547083).

CaseAddInfo:

CasePMIDs:

Case1: Newborn, Indian (consanguineous)

CasePresentingHPOs:

HPOFreeText: Identified by NBS with elevated C5-carnitine levels. Asymptomatic up to 3 year follow up. Levels of C5-carnitine decreased with time.

CaseNotHPOs:

CasePreviousTesting: Followup C5 carnitine 0.88 nM/ml (ref <0.8). Additional testing was performed on patients identified by NBS: all either had elevation of 2-methylbutyrlglycine in urine (with no intermediates consistent with isovaleric acidemia), or increase in 2-methylbutyrylcarnitine in culture from fibroblasts.

CaseGenotypingMethod: Bidirectional sequence analysis of genomic DNA.

Variant: NM_001609.3(ACADSB):c.295C>T (p.Gln99Ter) (homozygous)

ClinVar: 281177

gnomAD: 0.00006537 South Asian

VariantEvidence: LOF

CaseAddInfo:

CasePMIDs:

Case5: Female, 3.5 (report), European

CasePresentingHPOs: HP:0002194, HP:0000750, HP:0002370, HP:0002136, HP:0002066, HP:0002360, HP:0025401, HP:0012168, HP:0000252, HP:0000316, HP:0000426, HP:0000369, HP:0000347, HP:0002299, HP:0006801

HPOFreeText: Normal neonatal course. By 8 months could not crawl, subsequent gross motor development delayed. Speech and language delay. By 3.5 years showed balance problems, poor coordination, abnormal wide based gait with ataxia. Sleep disturbance , staring, behavioral issues since 1 year. Dysmorphic features noted at 3.5 years. Brain dysgenesis and partial seizure disorder.

CaseNotHPOs: No skeletal abnormaliites, no organomegaly.

CasePreviousTesting: Followup C5 carnitine 2.58 nM/ml (ref <0.63). Additional testing was performed on patients identified by NBS: all either had elevation of 2-methylbutyrlglycine in urine (with no intermediates consistent with isovaleric acidemia), or increase in 2-methylbutyrylcarnitine in culture from fibroblasts. Chromosome and fragile X testing normal as well as sequencing of exons 2 and 3 of MECP2. Plasma amino acids normal as well as Angelmann syndrome testing and microarray testing.

CaseGenotypingMethod: Bidirectional sequence analysis of genomic DNA.

Variant: NM_001609.3(ACADSB):c.303+1G>A (homozygous)

ClinVar: 203367

gnomAD: Other 0.0005549

VariantEvidence: Canonical splice site variant. Discrupts canonical splicing signal of intron 3.

CaseAddInfo:

CasePMIDs:

Case2: European

CasePresentingHPOs:

HPOFreeText: Identified by NBS with elevated C5-carnitine levels. Asymptomatic up to 3 year follow up. Levels of C5-carnitine decreased with time.

CaseNotHPOs:

CasePreviousTesting: Followup C5 carnitine 1.89 nM/ml (ref <0.63). Additional testing was performed on patients identified by NBS: all either had elevation of 2-methylbutyrlglycine in urine (with no intermediates consistent with isovaleric acidemia), or increase in 2-methylbutyrylcarnitine in culture from fibroblasts.

CaseGenotypingMethod: Bidirectional sequence analysis of genomic DNA.

Variant: 1. NM_001609.3(ACADSB):c.443C>T (p.Thr148Ile) 2. NM_001609.3(ACADSB):c.1159G>A (p.Glu387Lys)

ClinVar: 1. 9202 2. 9203

gnomAD: 1. South Asian 0.002678 2. Latino 0.0004797

VariantEvidence: 1. Decreases ACADSB enzymatic activity to 2.8% of wild type in vitro 2. In vitro expression of c.1159G>A in E. coli shows no protein on Western blot, reduced enzymatic activity to 2% and defects in protein folding and stabilit

CaseAddInfo: No info on cis or trans. Also heterozygous for p.R13K polymorphism.

CasePMIDs:

Case4:

CasePresentingHPOs:

HPOFreeText: Identified by NBS with elevated C5-carnitine levels. Asymptomatic up to 3 year follow up. Levels of C5-carnitine decreased with time.

CaseNotHPOs:

CasePreviousTesting: Followup C5 carnitine 2.58 nM/ml (ref <0.63). Additional testing was performed on patients identified by NBS: all either had elevation of 2-methylbutyrlglycine in urine (with no intermediates consistent with isovaleric acidemia), or increase in 2-methylbutyrylcarnitine in culture from fibroblasts.

CaseGenotypingMethod: Bidirectional sequence analysis of genomic DNA.

Variant: NM_001609.3(ACADSB):c.303+1G>A (homozygous)

ClinVar: 203367

gnomAD: Other 0.0005549

VariantEvidence: Canonical splice site variant. Discrupts canonical splicing signal of intron 3.

CaseAddInfo:

CasePMIDs:

Case3:

CasePresentingHPOs:

HPOFreeText: Identified by NBS with elevated C5-carnitine levels. Asymptomatic up to 3 year follow up. Levels of C5-carnitine decreased with time.

CaseNotHPOs:

CasePreviousTesting: Followup C5 carnitine 0.25 nM/ml (ref 0.33). Additional testing was performed on patients identified by NBS: all either had elevation of 2-methylbutyrlglycine in urine (with no intermediates consistent with isovaleric acidemia), or increase in 2-methylbutyrylcarnitine in culture from fibroblasts.

CaseGenotypingMethod: Bidirectional sequence analysis of genomic DNA.

Variant: 1. NM_001609.3(ACADSB):c.621G>A (p.Trp207Ter) 2. unknown

ClinVar: 299075

gnomAD:

VariantEvidence: Genomic DNA showed heterozygosity for this variant, but cDNA indicated homozygosity. The variant on the second allele must result in loss of transcription, abnormal splicing, unstable RNA, or deletion containing exon 5.

CaseAddInfo:

CasePMIDs:

PMID: 20547083

Gene: ACADSB

Disease: 2-methylbutyrylglycinuria

MonDO: MONDO:0012392

InheritancePattern: AR

Case2: 8 days onset

CasePresentingHPOs:

HPOFreeText: Identified by after metabolic studies performed for evaluation of clinical disease.

CaseNotHPOs:

CasePreviousTesting: DBS C5 carnitine 0.97 umol/L (ref <0.46); plasma alloisoleucine 1.5 umol/L (ref <2.1); urine C5 carnitine 35.8, 80.6 umol/mmol creatine (ref <3.0); urine 2-EHA 116, 132 U (ref <5); urine 2-MBG 20.2, 36.7 (ref <2.3); urine 2-methylbutyric acid conjugates as R-isomer 45%, 43% (ref 43-56%).

CaseGenotypingMethod: PCR amplification and sequencing of genomic DNA (entire coding region) from patient and available family members.

Variant: NM_001609.3:c.908G>C (p.Gly303Ala) (homozygous)

CAID: CA378620840

gnomAD: European (non-Finnish) 0.00002323

VariantEvidence:

CaseAddInfo:

CasePMIDs:

Case3: 11 months onset

CasePresentingHPOs:

HPOFreeText: Identified by after metabolic studies performed for evaluation of clinical disease.

CaseNotHPOs:

CasePreviousTesting: DBS C5 carnitine 1.75 umol/L (ref <0.46); urine C5 carnitine 2.7 umol/mmol creatine (ref <3.0); urine 2-EHA 32, 8, 15 U (ref <5); urine 2-MBG 14.5 umol/mmol creatine (ref <2.3); urine 2-methylbutyric acid conjugates as R-isomer 46%, (ref 43-56%).

CaseGenotypingMethod: PCR amplification and sequencing of genomic DNA (entire coding region) from patient and available family members.

Variant: NM_001609.3:c.443C>T (p.Thr148Ile) (homozygous)

ClinVar: 9202

gnomAD: South Asian 0.002678

VariantEvidence: Decreases ACADSB enzymatic activity to 2.8% of wild type in vitro (PMID: 20547083).

CaseAddInfo:

CasePMIDs:

Case4: 6 years onset

CasePresentingHPOs:

HPOFreeText: Identified by after metabolic studies performed for evaluation of clinical disease.

CaseNotHPOs:

CasePreviousTesting: DBS C5 carnitine 0.5, 0.55 umol/L (ref <0.46); urine 2-EHA 152, 19, 43 U (ref <5).

CaseGenotypingMethod: PCR amplification and sequencing of genomic DNA (entire coding region) from patient and available family members.

Variant: NM_001609.3:c.1102T>C (p.Ser368Pro) (homozygous)

CAID: CA5730911

gnomAD: Ashkenazi Jewish 0.002200; Overall 0.0002488

VariantEvidence:

CaseAddInfo:

CasePMIDs:

PMID: 15615815

Gene: ACADSB

Disease: 2-methylbutyrylglycinuria

MonDO: MONDO:0012392

InheritancePattern: AR

Case1: Newborn

CasePresentingHPOs:

HPOFreeText: Identified by NBS and is healthy with normal development.

CaseNotHPOs:

CasePreviousTesting: DBS C5 carnitine 1.2, 2.5, 1.1 umol/L (ref <0.46); plasma alloisoleucine 2.6 umol/L (ref <2.1); urine C5 carnitine 84.4, 58.1, 64.8 umol/mmol creatine (ref <3.0); urine 2-EHA 36, 31, 22 U (ref <5); urine 2-MBG 36.3, 29.3, 35.2 (ref <2.3); urine 2-methylbutyric acid conjugates as R-isomer 45%, 40% (ref 43-56%).

CaseGenotypingMethod: PCR amplification and sequencing of genomic DNA (entire coding region) from patient and available family members.

Variant: 1. NM_001609.3:c.1165A>G (p.Met389Val), 2. NM_001609.3:c.848A>G (p.Tyr283Cys)

CAID: 1. CA5730948; 2. CA5730830

gnomAD: 1. East Asian 0.0005513; 2. East Asian 0.0007068

VariantEvidence:

CaseAddInfo: In trans

CasePMIDs:

Case#: Patient 2, caucasian, 3 days (onset)

CasePresentingHPOs:

HPOFreeText: 3 days: hypoglycemia, poor feeding, lethargy, hypothermia. MRI: bilateral areas of subacute ischemia, increased T1 signal in lentiform nuclei consistent with global hypoxia. 1 year MRI: evolving areas of ischemia, thinning of gyri, delayed myelination of corpus callosum. 4 years: developmental delay, epilepsy. 6 years: unable to crawl or walk recurrent ear infections, chronic sinusitis, left eye extropia, microcephaly.

CaseNotHPOs: Normal neonatal EEG

CasePreviousTesting: 3 days: increased 2-methylbutyrylglycine (urine), 2-methylbutyrylcarnitine in plasma (C5-carnitine 1.4-2.4 uM, ref <0.4 uM)., elevated short chain carnitine to free carnitine (1.0, ref <0.5), normal blood amino acids. SBCAD enzyme activity in fibroblasts: 0.1 nmol/min/mg, ref. 0.16-0.29 nmol/min/mg).

CaseGenotypingMethod: Genomic DNA sequencing of all exons and part of flanking introns.

Variant: 1. NM_001609.3(ACADSB):c.303+3A>G 2. NM_001609.3(ACADSB):c.763C>T (p.Leu255Phe)

ClinVar: 1. 448980 2. 9200

gnomAD: 1. Not in gnomAD 2. Not in gnomAD

VariantEvidence: Skipping of exon 3 confirmed by mRNA analysis and minigene assay.This leads to a shifted reading frame with a PTC and likely NMD (when mRNA from patient 2's fibroblasts, who is het. for the variant, was analyzed, they saw no product from the mutant allele). CIS OR TRANS??

CaseAddInfo: Sister was also diagnosed with SBCADD prenatally and has been treated since birth. She has no clinical symptoms.

CasePMIDs: 10832746

Case#: Patient 1, Somalia, birth

CasePresentingHPOs: HP:0002104, HP:0001250, HP:0001263, HP:0008947

HPOFreeText: At birth, GC/MS of urine showed elevated 2-methylbutyrylglycine and 2-ethylhydracrylic acid, mildly elevated lactate. Plasma carnitine profile normal. NBS blood spot: high normal acylcarnitine profile (0.39 uM C5-acylcarnitine, ref <0.4 uM). 6 weeks: apena. 6 months: seizures, decline around 10 months, normal CT cerebrum. 7 months: protein-restricted diet. 8 months: normal EEG, infantile spasms. 9 months: global developmental delay, hypotonia. 10 months: sparse eye contact.

CaseNotHPOs: Normal chromosome analysis, cytomegalovirus (CMV) negative, normal hearing and vision, no skin changes.

CasePreviousTesting: SBCAD enzyme activity in fibroblasts: 0.17 +/- 0.01 nmol/min/mg, ref. 0.54-0.79 nmol/min/mg).

CaseGenotypingMethod: Genomic DNA sequencing of all exons and part of flanking introns.

Variant: NM_001609.3(ACADSB):c.303+3A>G

ClinVar: 448980

gnomAD: Not in gnomAD

VariantEvidence: Skipping of exon 3 confirmed by mRNA analysis and minigene assay.This leads to a shifted reading frame with a PTC and likely NMD (when mRNA from patient 2's fibroblasts, who is het. for the variant, was analyzed, they saw no product from the mutant allele).

CaseAddInfo:

PMID: 17883863

Gene: ACADSB

Disease: 2-methylbutyrylglycinuria

MonDO: MONDO:0012392

InheritancePattern: AR

Case: 4 years (Dx), male, Somali

CasePresentingHPOs: HP:0001250, HP:0000750, HP:0000817, HP:0008762

HPOFreeText: 5 months: seizure-like movements, stopped at 8 months with antieplieptic drug. Delayed speech. Protein restricted diet for 5 months with no improvement.

CaseNotHPOs: Normal growth and motor development. 5 years: no dysmorphic features. Normal muscle tone, strength, coordination and deep tendon reflexes. Eye exam, hearing test, EEG, EKG, and MRI normal.

CasePreviousTesting: Blood glucose, urea, creatinine, and liver transaminases normal. Normal chromosome analysis. Southern blot for Angelman syndrome negative. Urine analysis showed large amounts of 2-methylbutyryl glycine. Increased plasma level of C5-acylcarnitine (1.43 micromoles/L, reference range 0.05–0.38) and an increased C5/C3-acylcarnitines ratio of 2.83 (reference range 0.16–0.73).

CaseGenotypingMethod: PCR of all exons and flanking intron sequences of genomic DNA. Mother was also sequenced.

Variant: NM_001609.3(ACADSB):c.303+3A>G

ClinVar: 448980

gnomAD:

VariantEvidence: Functional studies demonstrate that the c.303+3A>G variant causes complete exon skipping of exon 3 (Madsen et al., 2006).

CaseAddInfo:

CasePMIDs:

GroupID: 15

Case: 23Y0M, Sex Unknown, Ethnicity Unknown

DiseaseAssertion: assumed VHL

FamilyInfo: 1 of the 573 patients discussed in this paper were found to have this variant. This mutation was found in 1 VHL family with a single patient.

CasePresentingHPOs: HP:0009711; HP:0006880 (retinal capillary hemangioma; cerebellar hemangioblastoma)

CaseHPOFreeText: patient had retinal angiomas at 21Y and cerebellar hemangioblastomas diagnosed at 23Y

CaseNotHPOs: HP:0005584; HP:0002666 (renal cell carcinoma; pheochromocytoma)

CaseNotHPOFreeText: N/A

CasePreviousTesting: N/A

PreviouslyPublished: N/A

SupplementalData: Supplementary Table S1.

Variant: p.F91* (c.272_273delinsAA)

CaseProblemVariantFreeText: c.272T>A and c.273C>A results in c.272_273delinsAA

LegacyVariant: N/A

ClinVarID: CA2499307077 http://reg.clinicalgenome.org/redmine/projects/registry/genboree_registry/by_caid?caid=CA2499307077

CAID: N/A

gnomAD: N/A

VariantEvidence: N/A

MutationType: delins; stop_gained

CivicName: F91* (c.272_273delinsAA)

MultipleGeneVariants: N/A

Case#: 3 years (report), male, Pakistan

CasePresentingHPOs: HP:0008947, HP:0001270, HP:0003700, HP:0000486, HP:0008315, HP:0011936

HPOFreeText: Became increasingly floppy in 2nd year of life, able to walk with support at 3 years, normal MRI (2 years), urinary organic acid consistently showed 2-methylbutyrylblycinuria with excretion of trace amounts of isobutyrylglycine. NBS blood spot showed normal acylcarnitine profile.

CasePreviousTesting: Total RNA extracted from fibroblasts, cDNA synthesized, PCR amplification of entire coding region of SBCAD cDNA and ACAD-8 cDNA, bidirectional sequencing. Enzyme activity of ACAD toward 2-methylbutyryl-CoA in fibroblasts was 10% of controls (0.016 nmol/min/mg protein vs 0.157 nmol/min/mg protein).

CaseGenotypingMethod: PCR and sequencing of ACADSB cDNA, followed by genomic DNA.

Variant: NM_001609.3(ACADSB):c.1228G>A (p.Gly410Ser)

ClinVar: 9199

gnomAD: 0.00002949 overall (no homozygotes)

VariantEvidence: The 1228G>A variant is in the last nucleotide in the skippped exon 10. cDNA analysis from the patient showed no normal-sized ACADSB mRNA. Northern blot of total RNA from fibroblasts showed normal levels of mRNA.

CaseAddInfo: Patient also heterozygous for the SCAD A625 polymoprhism (Corydon, 1996). Healthy father and siblings were heterozygous for the deletion, while mother was also homozygous and found to excrete 2-methylbutyrylglycine in her urine.