Table 3.

Likely diagnoses in the first 1133 families

		Reviewed (SNV, CNV)	Reported as likely diagnostic	Predictive value of flag (%)	Diagnostic yield (%; n=1133)
Autosomal dominant
	De novo	242 (193, 49)	184	75%	16%
	Inherited	528 (473, 55)	27	5%	2%
Autosomal recessive
	De novo	6 (6, 0)	0	..	..
	Inherited	425 (424, 1)	52	13%	5%
X-linked
	De novo	41 (36, 5)	31	75%	3%
	Inherited	371 (360, 11)	23	6%	2%
Uncertain inheritance		83 (0, 83)	0	..	..
Chromosomal events
	Uniparental disomy	..	6	..	0·5%
	Mosaicism	..	5	..	0·5%
Total		1696	328	19%	27%*

See appendix 2 for details of individual genes and phenotype classes. The predictive value is the probability that a flagged variant was reported as likely diagnostic (reported or reviewed), and the diagnostic yield is the contribution of that type of variant to the overall diagnostic yield. Note that three pairs of siblings and two pairs of monozygotic twins received the same diagnosis. Only 14% of reported variants were present in the public Human Gene Mutation Database or Leiden Open Variation Database; 84% of flagged variants present in these databases were not reported, because they did not appear to be relevant to the child's phenotype. SNV=single nucleotide variant. CNV=copy number variant.

^*17 probands received two contributory pathogenic variants.