Table 1.
Clinical features, laboratory findings and molecular characterization of the six HPS families studied.
| Family | Patients | Bleeding symptoms | Other clinical features | BS | Platelet dense granule analysis | Electron microscopy | Disease-causing variants |
|---|---|---|---|---|---|---|---|
| 1 | P1: 13 y, female P2: 16 y, female No familial consanguinity |
P1 + P2: Epistaxis, ecchymosis, menorrhagia P1: GI, and post-surgery |
Both: OCA P1: Crohn’s disease |
P1: 11 P2: 3 |
P1 and P2: 70% reduction in TRAP-induced CD63 release 15–25% reduction in 14C-5HT uptake |
Severe reduction of δ granules |
HPS4: c.2054delC ((p.Pro685Leufs*17) |
| 2 | P3: 40 y, female P4: 48 y, female Familial consanguinity |
P3 + P4: easy bruising and epistaxis P3: GI bleeding |
Both: OCA and nystagmus P3: Colectomy P4: Pulmonary fibrosis |
P3: 7 P4: 6 |
– | – |
HPS4: c.272T > C (p.Leu91Pro) |
| 3 | P5: 25 y, male No familial consanguinity |
Epistaxis, ecchymosis and GI | OCA and strabismus Angiodysplasias |
P5: 5 | Absent TRAP- induced CD63 release 68% reduction in 14C-5HT uptake |
Severe reduction of δ granules |
HPS3: c.2464C > T (p.Arg822*) |
| 4 | P6: 26 y, male P7: 56 y, female No familial consanguinity |
P6 + P7: Epistaxis, easy bruising and after teeth extractions | Both: OCA and nystagmus | P6: 6 P7: 8 |
P6 and P7: 58% and 37 reduction in TRAP-induced CD63 release 48% reduction in 14C-5HT uptake |
Severe reduction of δ granules |
DTNBP1: c.307C > T (p.Gln103*) |
| 5 | P8: 18 y, female No familial consanguinity |
Easy bruising, minor wounds, menorrhagia and after teeth extractions | OCA, strabismus, nystagmus, deep visual deficiency and exotropia and torticollis | P8: 7 | Absence ATP release with ADP (10 μM), Col (2 μg/mL) and AA (1 mM) | Absence of δ granules |
DTNBP1 c.307C > T (p.Gln103*) |
| 6 | P9: 9 y, male P10: 13 y, female Familial consanguinity |
P9 + 10: Epistaxis, easy bruising and minor wounds P10: menorrhagia |
Both: OCA, nystagmus, deep visual deficiency P10: epilepsy and mild mental retardation |
P9: 6 P10: 8 |
P9 and P10: absence ATP release with ADP (10 μM), Col (2 μg/mL) and AA (1 mM) | Severe reduction of δ granules |
HPS6 c.60_64dup (p.Leu22Argfs*33 |
F: family; P: patient; y: years old; GI: gastrointestinal; BS: bleeding score; OCA: oculocutaneous albinism; TRAP: thrombin receptor-activating peptide, Epi: epinephrine; AA: arachidonic acid; Col: collagen; Risto: ristocetin, 5HT: Serotonin.