Identification of two novel COL10A1 heterozygous mutations in two Chinese pedigrees with Schmid-type metaphyseal chondrodysplasia

Table 1 Clinical and genetic features of affected individuals

Pedigree	Patient	Gender	Age (years old)	Onset age (months old)	Height (SD)	Severity of disease^a	Pathogenic mutation
Family 1	I:2	Female	Death	12–18	−0.8	Not available	Not available
	II:1	Male	82	Not available	+ 0.4	Mild	c.1765 T > A
	III:1	Male	57	6–8	−2.2	Severe	c.1765 T > A
	III:9	Male	52	~ 12	−1.1	Moderate	c.1765 T > A
	III:11	Male	50	10–12	−1.6	Moderate	c.1765 T > A
	IV:1	Male	33	10–12	−0.4	Mild	c.1765 T > A
	IV:4	Female	28	~ 12	−1.3	Mild	c.1765 T > A
	IV:13	Male	29	6–8	+ 0.1	Moderate	c.1765 T > A
	V:2^#	Male	2	~ 6	−4.2	Severe	c.1765 T > A
	V:4	Male	4	6–8	−2.5	Severe	c.1765 T > A
Family 2	I:1	Male	Death	Not available	−0.4	Not available	Not available
	II:2	Female	77	~ 12	−0.8	Mild	c.1846A > G
	II:3	Male	72	10–12	−1.5	Moderate	c.1846A > G
	III:1	Male	51	~ 12	−1.1	Mild	c.1846A > G
	III:3	Male	48	10–12	−1.8	Moderate	c.1846A > G
	III:9	Male	49	8–10	−1.9	Moderate	c.1846A > G
	IV:1	Male	24	6–8	−1.5	Severe	c.1846A > G
	IV:4	Female	27	~ 12	−0.7	Mild	c.1846A > G
	IV:9	Female	25	10–12	−1.2	Mild	c.1846A > G
	V:1^#	Male	1.5	6–8	−4.1	Severe	c.1846A > G

^a “Mild” indicates that the patients exhibit i) short stature (mean - 1.5 SD < Height < mean - 0.5 SD) without evident abnormal clinical or radiographic manifestations, or ii) mild genu varum was involved. “Moderate” patients represent that i) mean - 2.5 SD < Height ≤ mean - 1.5 SD, or ii) similar typical radiographic manifestation as illustrated in Additional file 4. “Severe” patients show that i) short stature (Height ≤ mean - 2.5 SD), ii) similar radiographic findings to severe manifestation shown in Additional file 4, or iii) unbearable clinical symptoms, such as arthralgia and restricted motion of the joints. ^# Proband of each pedigree

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