Interstitial deletion of 1p22.2p31.1 and medium-chain acyl-CoA dehydrogenase deficiency in a patient with global developmental delay.
We report on a 6-year-old girl who presented at 6 months of age with seizures, delayed psychomotor development and mild facial dysmorphism. A small muscular ventricular septal defect was documented on echocardiogram and brain MRI showed a frontal brain anomaly. Urine organic acid analysis revealed dicarboxylic aciduria, and plasma acylcarnitine analysis showed marked elevation of octanoyl (C8) and decanoyl (C10) carnitines with C8:C10 ratio of 9:1. These results were indicative of medium chain acyl-CoA dehydrogenase deficiency. ACADM gene sequencing showed an apparent homozygous c.166G > C (Ala31Pro) missense mutation in exon 3; however, only the mother was found to be a carrier of this novel missense mutation. This finding along with non-regressive developmental delay prompted further karyotype and genomic investigations. An interstitial deletion of chromosome 1 was detected by repeat G-banding: 46,XX,del(1)(p22.2p31.1). Parental karyotypes were normal. The deletion was characterized by array CGH analysis using a 1 Mb BAC/PAC array platform. Clones deleted extended from RP11-88B10 (1p31.1) to RP5-1007M22 (1p22.2), a 15.5 Mb deletion which includes the ACADM locus. Clinical review of 6/7 cases of interstitial deletions with breakpoints of 1p22 and 1p31/32, including the patient in this report, indicate a variable phenotype. Thus, although G-band breakpoints are similar, common breakpoints for these alterations are unlikely. This is the first report of a patient with fatty acid oxidation defect caused by a mutation in combination with an interstitial chromosomal deletion.
Maegawa
Gustavo H B
GH
Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada. gustavo.maegawa@sickkids.ca
Poplawski
Nicola K
NK
Andresen
Brage Storstein
BS
Olpin
Simon E
SE
Nie
Gloria
G
Clarke
Joe T R
JT
Teshima
Ikuko
I
D042964:Acyl-CoA Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D002331:Carnitine / Q000031:analogs & derivatives / Q000097:blood; D002648:Child; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D004252:DNA Mutational Analysis; D003998:Dicarboxylic Acids / Q000652:urine; D005091:Exons; D019066:Facies; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D020125:Mutation, Missense; D020411:Oligonucleotide Array Sequence Analysis; D011596:Psychomotor Disorders / Q000175:diagnosis / Q000201:enzymology* / Q000235:genetics*; D012640:Seizures / Q000175:diagnosis / Q000201:enzymology* / Q000235:genetics*
D003998:Dicarboxylic Acids; C116917:acylcarnitine; D042964:Acyl-CoA Dehydrogenase; D002331:Carnitine