GNAS and alpha thalassemia spectrum: One case was homozygous for the HBA2 variant [NM_000517.6: c.377T>C(p.Leu126Pro)], which was inherited from both parents, and was diagnosed with alpha thalassemia; the other patient carried a de novo GNAS variant [NM_000516.7: c.139G>A(p.Gly47Ser)] and was diagnosed with pseudohypoparathyroidism Ia.