• Age \> 12 and \< 35 years. Patients of age 2-12 and 35-50 years will be included after 8 patients reach day 100 without TRM and if ≥ 4 of the first 8 patients reach day 100 without graft failure or grade III-IV acute GvHD.

• Suitable haploidentical donor.

• Performance score ≥ 70% by Karnofsky Performance Scale or 0 to 1 by ECOG (age \> 16 years), or Lansky Play-Performance Scale ≥ 70% (age ≤ 16 years).

• Adequate major organ system function as demonstrated by:

‣ For patients ≥ 18 years of age:

⁃ eGFR ≥ 50 mL/min by Cockcroft-Gault formula

⁃ For patients \< 18 years of age:

⁃ Serum creatinine clearance: glomerular filtration rate \[GFR\]) must be \>50 mL/min/1.73 m2 as calculated by the Schwartz formula

• Conjugated (direct) bilirubin less than 2x upper limit of normal.

• ALT or AST ≤ 3 times institutional upper limit of normal.

• Left ventricular ejection fraction ≥ 50%.

• Diffusing capacity for carbon monoxide (DLCO) ≥ 50% predicted, corrected for hemoglobin. For children \< 7 years of age who are unable to perform PFT, oxygen saturation \> 92% on room air by pulse oximetry.

• For SCD patients: HbSS, HbSC, HbS/β° with one or more of the following complications:

‣ Acute chest syndrome: 2 or more episodes in the 2 years preceding enrollment

⁃ Vaso-occlusive episodes: 3 or more episodes in the 2 years preceding enrollment

⁃ Recurrent priapism: 2 or more episodes in the 2 years preceding enrollment

⁃ History of osteomyelitis or osteonecrosis

⁃ Cerebrovascular disease:

• Imaging evidence of prior overt or silent stroke

• History of a neurologic event resulting in focal neurologic deficits lasting \> 24 hours

• Abnormal transcranial Doppler: Timed average maximum mean velocity ≥ 200 cm/sec in terminal portion of the carotid or proximal portion of the middle cerebral artery or \> 185 cm/sec plus evidence of intracranial vasculopathy if imaging TCD is used

‣ Pulmonary hypertension: Confirmed by right heart catheterization with mean pulmonary arterial pressure ≥ 25 mmHg or mean pulmonary vascular resistance \> 2 Wood units

⁃ Red blood cell alloimmunization (\> 3 alloantibodies)

• For thalassemia patients: Any genotype, with all of the following:

‣ Onset of red blood cell transfusion dependence during the first 3 years of life

⁃ RBC transfusion history \> 225 mL/kg/year or \> 15 lifetime RBC transfusions

⁃ Pre-transfusion hemoglobin ≤ 7 g/dL

⁃ Hepatosplenomegaly

• Patient or the patient's legal representative, parent(s) or guardian should be able to provide written informed consent. Assent of a minor if participant's age is at least seven and less than eighteen years.

• For sexually active men and women of childbearing potential, must agree to use a form of contraception considered effective and medically acceptable by the Investigator.