MEIS2 (15q14) gene deletions in siblings with mild developmental phenotypes and bifid uvula: documentation of mosaicism in an unaffected parent

Table 1 Clinical features associated with different MEIS2 variants

	MEIS2 dels/dups^#	MEIS2 mutations^&	Patient A^#	Patient H^#	II-2; II-3	I-1
Mutation size/coordinates^$	Variable	SNVs and indels	194 Kb/chr15:36989551_37184183	2.92 Mb/chr15:34308789_37231638	423 Kb/chr15: chr15:36808211-37231497
Mutation size/coordinates^$	Variable	SNVs and indels	194 Kb/chr15:36989551_37184183	2.92 Mb/chr15:34308789_37231638	Non-mosaic	Mosaic
Mutation types	Disruption including exon 9*	7 nonsense; 6 missense; 3 splicing; 2 in-frame del; 2 frameshift mutation	Exon 12 deletion*	Exon 10–12 deletion*	Exon 10–12 deletion*
Inheritance Mode	19 de novo; 2 familial;8 NA	18 de novo/2 pat	de novo	de novo	pat	de novo
Palate defects	22/26; 1 NA	16/20	−	−	Bifid uvula	−
Cardiac defects	10/26; 1 NA	13/18; 2 NA	−	−	−	ASD
Developmental delay	+	+	+	+	Mild	−
Walked@	14mo-4y	18mo (Giliberti et al. 2020); 26mo (11 cases reviewed in Verheije et al., 2019); 30mo (Santoro et al. 2021); 32mo (Su et al. 2020); NA (6 cases from Srivastava et al. 2018, Hildebrand et al. 2020, Douglas et al. 2018)	27mo	30mo	II-2: 18mo; II-3: 21mo	−
Facial features	Variable: 10/12 (14 cases from Verheije et al. 2019)	Variable; 17/17; 3 NA	−	Anteverted nares, asymmetric ears with abnormal helix	−	−
Intellectual disability	19/21; 8 NA	20/20	+	+	NA	−

NA not available, + phenotype observed, − phenotype not observed, ASD atrial septal defect, SNV single nucleotide variant, dels/dups microdeletions/microduplications, indels small insertion/deletions, pat paternal, mo months, y years
^#Reference [2]—Verheije et al. (2019)
^&Reference [2]—Verheije et al. (2019) [14],—Douglas et al. (2018), [15]—Giliberti et al. (2020), [18]—Hildebrand et al. (2020), [19]—Su et al. (2020), [20]—Fujita et al. (2016), [21]—Santoro et al. (2021), [22]—Srivastava et al. (2018)
^$Genomic coordinates are based on the genome assemble GRCh37/hg19
*Exon definition is based on the NM_170676.5 transcript

ISSN: 1755-8166