Amelogenesis imperfecta

Gene: SMOC2

Green List (high evidence)

PMID: 22152679 Bloch-Zupan et al., 2011
Report of a severe developmental dental defect that results in a dentin dysplasia phenotype with major microdontia, oligodontia, and shape abnormalities in a highly consanguineous family. 2 affected children were found to carry a homozygous mutation in SMOC2: c.84+1G>T. Unaffected sibs were heterozygous for the variant. Method: Homozygosity mapping, WES, direct sequencing - SMOC2 was poorly covered on exome.
Knockdown of smoc2 in zebrafish showed pharyngeal teeth that had abnormalities reminiscent of the human phenotype.

PMID: 23317772 Alfawaz et al., 2013
Consanguineous Pakistani family with oligodontia and microdontia. WES detected a homozygous SMOC2 c.681T>A (p.C227X) mutation in 2 affected individuals.

PMID: 32908163 Morkmued et al., 2020
Same group as PMID: 22152679 Bloch-Zupan et al.
Follow up of a 9yo female patient from the 2011 study. Radiographs showed severe oligodontia, microdontia, tooth root deficiencies, alveolar bone hypoplasia, and some skeletal dysplasia features: hyperlordotic curved spinal column, platyspondyly, wider iliac wings.
Mouse model: homozygous smoc2 mutant mice had tooth number anomalies, reduced tooth size, altered enamel prism patterning, and spontaneous age-induced periodontal bone and root loss, supportive of disease association.

SMOC2 is associated with AR Dentin dysplasia, type IA, OMIM:125400 in OMIM (accessed 5th Jun 2026).
Sources: Literature

Created: 5 Jun 2026, 4:16 p.m. | Last Modified: 5 Jun 2026, 4:28 p.m.

Panel Version: 4.35

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Dentin dysplasia, type IA, OMIM:125400; atypical dentin dysplasia due to SMOC2 deficiency, MONDO:0017819; dentin dysplasia type 1 with microdontia and shape anomalies

Publications

• 22152679
• 23317772
• 32908163