Large heterozygous PARN deletions can be tolerated without neuropsychiatric disorders but may feature cytopenias. (A) Schematic of the genomic region surrounding the deletion and location and distribution of the microarray probes. The genomic region displayed here ranges from 14.4 to 14.9 Mb on the short arm of chromosome 16. All 6 protein-coding genes and their distribution of exons are shown in the upper part of the schematic. The middle part includes the deletions of proband 832 III.1 and proband 1210 II.1 found in our study (red bars) determined by microarray and/or quantitative real-time PCR. The distal breakpoint of the deletion ex1-21 is located upstream of PARN within the dashed bar between exon 4 of PLA2G10 and exon 13 of NOMO1. The blue bars indicate the previously described 4 intragenic deletions of PARN in the study from Dhanraj et al⁴⁵  with the proximal breakpoint in patient 4 located further downstream (dashed bar). The green bar represents the previously reported whole-gene deletion in the study from Moon et al⁴⁶  with both the proximal and distal breakpoints located outside of the gene schematic (dashed bar). The bottom part displays the distribution and location of the microarray probes used for proband 832 III.1. The mean log₂ ratio of the deleted probes is −0.65, and the deleted region is highlighted with a red bar. (B) Mapping of the distal breakpoint. Quantitative real-time PCR results of the relative copy number of exon 17 of PARN, exon 1-8 of BFAR, exon 4 of PLA2G10, and exon 13 of NOMO1 compared with the non-deleted exon 22 of PARN. Values at or around 0.5 indicate a heterozygous loss, and values at or around 1 indicate the presence of both alleles. (C-D) Pedigrees of a large family with a heterozygous deletion of exons 1-21 of the PARN gene and a family with a single exon PARN deletion. A circle represents a woman, and a square represents a man. Roman numerals indicate generations (eg, I, II, III, IV). A slash through the circle or square indicates that the person is deceased. The proband is indicated by the arrow. The variant carrier status is mut/+ for carriers and +/+ for wild type. OC indicates an individual who is an obligate carrier of the familial PARN deletion. The phenotype is detailed below the symbol. The pedigree number and variant found in each family are noted above the pedigree.