Table 1.

NF1 gene dosage in bone marrows of children with NF1 and malignant myeloid disorders

				Parental origin
Patient no.	Sex	Age at onset, mo	Diagnosis	NF1 mutation	LOH at NF1 locus	NF1 gene dosage value*†	Predicted NF1 gene copy no.‡
1	M	9	MPS	Paternal	Maternal	0.99	Disomy
2	M	10	AML	Paternal	Maternal	0.93	Disomy
3	M	24	Monosomy 7	Unknown	Maternal	0.96	Disomy
4	M	14	JMML	Maternal	Paternal	0.86	Disomy
5	F	30	JMML	Maternal	Paternal	0.94	Disomy
6	M	10	JMML	Maternal	Paternal	0.87	Disomy
7	M	5	Monosomy 7	Maternal	Paternal	0.90	Disomy
8	F	18	MPS	Paternal	Maternal*	0.85	Disomy
9	M	60	JMML	Maternal	Paternal	0.57	Monosomy
10	M	19	Monosomy 7	De novo	Maternal*	0.48	Monosomy

Clinical descriptions, LOH, and NF1 mutation analyses have been reported previously for most of the patients.¹⁷-¹⁹

^*Data from this study employing quantitative PCR at NF1 gene segment

^†Measured in unfractionated bone marrow cells except in patients 3 and 9, for whom leukemic cells in peripheral blood were used

^‡Predicted gene copy number based on NF1 gene dosage values. Validation of the assay on nontumor DNA demonstrated that NF1 disomy gave dosage values of 0.98 ± 0.08 SD, while monosomy gave values of 0.45 ± 0.04 SD. A range of 2 SD was used to approximate a 95% confidence interval. Therefore, values from 0.82 to 1.14 predicted disomy, and values from 0.37 to 0.53 predicted monosomy