Enamel hypo-calcification and hypo-maturation of tooth is seen in:

Tricho-Dento-Osseous Syndrome  The tricho-dento-osseous (TOP) syndrome is a hereditary condition, which chiefly involves the hair, teeth, and bones. The condition is inherited as an autosomal dominant disorder and the mutations are mapped to the DLX gene located at chromosome 17q21.3-q22. DLX gene plays a role in the development of craniofacial bone in the early embryogenesis. Later, it is expressed in structures that involve epithelial-mesenchymal interaction such as teeth, hair follicle, and skin. The dental findings include yellow-brown discoloration of teeth, enamel hypoplasia, and severe attrition of enamel. Such defective enamel may be a cause for commonly occurring dental abscesses. Wide pulp chamber (taurdontism), especially involving the molars, has been reported. Radiographic Features  In dental X-rays, large pulp chambers are noticed, often in the molars. In addition, teeth may remain unerupted for long, leading to partial anodontia.  Key Concept: A pattern of teeth alteration similar to amelogenesis imperfecta with taurodontism is seen in the systemic disorder, tricho-dento-osseous syndrome. Reference:  Shafer’s Textbook of ORAL PATHOLOGY Eighth Edition page no 483