Analysis of fatal outcomes of patients with mucopolysaccharidosis type II according to the Russian mucopolysaccharidosis registry

Table 2 Comparison of disease’s features in alive/dead mucopolysaccharidosis type II patients, n (%)

Parameter	Total n = 160	Alive n = 140	Median (IQR); min-max	Dead n = 20	Median (IQR); min-max		P value
General information
Age at last observation1	160	140	10.7 (5.9; 15.9); 0.7-46.4	20	16.5 (12.5; 21); 9.0-43		0.001
Birth weight, kg	91	83	3.4 (3.2; 3.9); 1.5-4.7	8	3.9 (3.4; 4.3); 3.3-4.5		0.062
Height at birth, cm	117	103	53 (51; 54); 40-60	14	52 (51; 56); 49-57		0.609
Age of first symptom, years	128	112	1.0 (0; 2); 0-19.0	16	1.0 (0; 2); 0-8		0.982
Age at diagnosis, years	145	125	3.0 (2; 5); 0-32	20	5.0 (4; 7); 2-38		0.0006
Ever received ERT	152	133	118 (88.7)	19	16 (84.2)		0.569
Age of start ERT, years	117	101	5.0 (3; 9); 0-43	16	7.5 (6.5; 11.5); 4-39		0.004
Pathogenic SNP	118	102	59 (57.8)	13	8 (61.5)		0.532
Likely pathogenic SNP			34 (33.3)		5 (38.5)
VUS SNP			9 (8.8)		0 (0)
Neurology
Patients with a neuronopathic form	98/148	130	85 (65.4)	18	13 (72.2)		0.565
Psychomotor development delay (up to 1 year)	148	130	54 (41.5)	18	9 (50.0)		0.496
Delayed mental and speech development (1-3 years)	147	129	85 (65.9)	18	14 (77.8)		0.314
Intellectual disability: From mild to profound (5-12 years)	128	110	69 (62.7)	18	13 (72.2)		0.648
Intellectual disability: From mild to profound (after 12 years)	84	69	40 (58.0)	15	15 (66.7)		0.546
Hydrocephalus	131	116	18 (41.4)	15	11 (73.3)		0.019
Bypass surgery	133	119	0 (0)	14	1 (7.1)		0.003
Epilepsy	134	119	12 (10.1)	15	8 (53.3)		0.000009
Swallowing disorder	129	113	26 (23.0)	16	11 (68.8)		0.0002
Impossible independent walking (5-12 years)	136	120	12 (10.0)	16	2 (12.5)		0.757
Impossible independent walking (after 12 years)	82	68	15 (22.1)	14	8 (57.1)		0.002
Carpal tunnel syndrome	114	100	58 (58.0)	14	11 (78.6)		0.140
Somatic symptoms
Hurler phenotype	142	123	118 (95.9)	19	19 (100)	0.371
Hepatosplenomegaly	139	121	113 (93.4)	18	18 (100)	0.261
Hearing loss	126	113	76 (67.3)	13	12 (92.3)	0.062
Respiratory disorders	135	119	47 (39.5)	16	14 (87.5)	0.001
Tracheostomy	136	121	2 (1.7)	15	3 (20.0)	0.0004
Any hernias	136	118	98 (83.0)	18	18 (100)	0.059
Orthopedic problems
Any orthopedic features	140	121	119 (98.4)	19	19 (100)	0.573
Spinal involvement	132	117	76 (65.0)	15	13 (86.7)	0.091
Chest deformity	139	123	67 (54.5)	16	11 (68.8)	0.279
Cardiac disorders
Cardiac disorders (cardiomyopathy + myxomatous valve disease)	132	116	89 (76.7)	16	16 (100)	0.031
Cardiomyopathy	131	115	34 (29.3)	15	9 (60.0)	0.017
Myxomatous valve disease	130	115	78 (67.8)	15	15 (100)	0.009

¹For died patients – age of the death; IQR: Interquartile range (Q1; Q3); ERT: Enzyme replacement therapy; VUS: Variant of unknow significance; SNP: Single nucleotide polymorphism.