Table 1.
Summary of patient demographics and details of treatment with enzyme replacement therapy (ERT)
| Case 1 | Case 2 | Case 3 | Case 4 | Case 5 | Case 6 | Case 7 | Case 8 | |
|---|---|---|---|---|---|---|---|---|
| Consanguinity | N | N | N | N | N | N | N | N |
| Positive MPS II family history (Relationship to Case) | Sibling, maternal uncle | Sibling | Maternal second cousin | Sibling | Maternal half-uncle, maternal great-uncles, maternal first cousin once removed | None | Maternal uncles, maternal first cousin once removed | Maternal great-uncle |
| Gestational ultrasound findings | Normal | Ventriculomegaly | ND | ND | Polyhydramnios | Normal | Normal | Large for gestational age |
| Apgar score 1′/5′ | 9/10 | 8/9 | 8/10 | 9/9 | 6/9 | 9/10 | ND | ND |
| Birth weight in g, (percentile) | 3,320 (54) | 3,856 (92) | 3,050 (27) | 3,884 (93) | 3,005 (24) | 3,920 (95) | 2,900 (16) | 4,366 (>99) |
| Birth length in cm, (percentile) | 51 (72) | 52 (86) | 49 (31) | 52 (89) | 48 (16) | 51 (73) | 47 (7) | 53 (96) |
| Birth head circumference in cm, (percentile) | 34 (35) | 36 (89) | 33 (12) | 37 (98) | 33 (12) | 36 (89) | 33.6 (24) | ND |
| Age at diagnosis | Prenatal | 1 week | 6 weeks | 1 day | 4 weeks | 11 weeks | 1 week | 5.5 months |
| Genotype | p.R88H | p.R95G | p.P86L | p.R493P | c.1270insCC | p.G336E | c.1133A>G | c.1362-1365dup |
| Signs and symptoms at ERT baseline | Lumbar gibbus | Mild frontal bossing, hepatomegaly, lumbar kyphosis, pectus excavatum | Diastasis recti abdominis, hepatosplenomegaly, umbilical hernia | Mild coarse facies, hepatosplenomegaly, hearing loss, lumbar kyphosis | Coarse facies, Diastasis recti abdominis, hepatomegaly, umbilical hernia | Hydrocele, inguinal hernia, hepatomegaly, congestive heart failure | Mild frontal bossing, chronic otitis media with effusion, scapular flaring with right shoulder abduction | Mild coarse facies, small thickened ears, hepatomegaly, bilateral syndactyly of the second and third toes, gibbus; bilateral foot adduction, frequent upper respiratory infections, recurrent episodes of acute otitis media |
| X-Ray/MRI skeletal findings at ERT baseline | Lumbar gibbus at L3-L5 | Lumbar kyphosis, pectus excavatum, mild broadening of the ribs | ND | Mild focal kyphosis (apex at L2), anterior beaking of the caudal aspect of L2 | Normal | ND | ND | Thoracolumbar gibbus with the apex at L2, bilateral forefoot adductus |
| Echocardiography at ERT baseline | Normal | Mildly dilated left ventricle with low-normal systolic function and increased apical trabeculations | Normal | ND | Small atrial septal defect or stretched patent foramen ovale | Abnormal (See Table 2) | Normal | Normal |
| Age at ERT start | 1.5 weeks | 6 weeks | 8 weeks | 10 weeks | 11 weeks | 12 weeks | 6 months | 6.5 months |
| Dose in mg/kg/weekly infusion | 0.5 | 1.5 at first, reduced to 0.5 as the patient gained weightb | 0.6 mg for the first 8 infusions, and 0.5 mg for 9th and 10th infusionsb | 1.4 at first, reduced to 0.5 as the patient grewb | 0.5 | 0.5 | 0.5 | 0.66 at first, reduced to 0.5 as the patient gained weightb |
| Total duration of treatment | 6 weeks | 2 yearsa | 10 weeks | 3 yearsa | 5.5 yearsa | 20 monthsa | 4 yearsa | 3.5 yearsa |
| HSTC | Yes | No | Yes | No | No | No | No | No |
ERT enzyme replacement therapy, HSTC Hematopoietic stem cell transplantation, MPS II mucopolysaccharidosis II, ND no data
aDuration of treatment to date of last follow-up examination; patient currently continues on treatment
bOff-label use of the medication. The approved dose is 0.5 mg/kg weekly (Elaprase® prescribing information 2011)