Methylation analysis of 6q24, 7p12, 7q32, 11p15, 14q32, 15q11 and 20q13 by MS-MLPA
There are around 12 currently known imprinting disorders caused by abnormalities (sequence variants, CNVs, UPD or methylation defects) at imprinted regions on chromosomes 6q24, 7p12, 7q32, 11p15, 14q32, 15q11 and 20q13. A subset of patients with imprinting disorders have been found to have abnormal methylation at more than one locus, a condition termed Multi Locus Imprinting Disorder (MLID). Patients with MLID may have different or additional clinical features to those with an imprinting defect at a single locus. MLID is most common in Transient Neonatal Diabetes Mellitus caused by hypomethylation at PLAGL1:alt-TSS-DMR (6q24), Beckwith-Wiedemann syndrome caused by hypomethylation at KCNQ1OT1:TSS-DMR (ICR2; 11p15), Silver-Russell syndrome caused by hypomethylation at H19-IGF2:IG-DMR (ICR1; 11p15) and Pseudohypoparathyroidism type IB caused by methylation anomalies of the GNAS complex locus DMRs (20q13).
The laboratory participates in the GenQA Imprinting disorders EQA scheme.
NHSE test directory code: R417 Multi locus imprinting disorder. Testing criteria can be found here.