Three de novo losses and one insertion within a pericentric inversion of chromosome 6 in a patient with complete absence of expressive speech and reduced pain perception

A 32-year-old female patient, observed for 30 years because of a distinctive phenotype consisting of a dysmorphic face non-progressive deficit of motor control, lack of speech development, reduced sensitivity to pain, with a known, complex interstitial deletion 6q14 within a de novo pericentric inversion 6p11.2;q15, was re-examined at the molecular level. Applying the Infinium HumanHap300 BeadChip array and BAC-based FISH we found two new non-contiguous microdeletions in addition to the one detected previously by high resolution G-band analysis. A 360 kb loss in band 6p12.3, containing the genes RHAG, CRISP1, 2, and 3, and PGK2, a 1.15 Mb loss in 6p12.2-p12.1, containing the genes PKHD1, IL17, MCM3, EFHC1, and TRAM2 genes, and an 11.9 Mb loss in region 6q14.3-q16.1, reported previously, were mapped on the rearranged chromosome 6. The latter loss contained the central cannabinoid receptor isoform b (CNR1), which may be involved in brain development and function. Since the maternal SNPs were retained this rearrangement of chromosome 6 is most likely of paternal origin.