Amelogenesis imperfecta

Gene: FAM20A

Green List (high evidence)

Currently on the Leeds AI diagnostic panel (Contact: Ruth Charlton). Associated with hypomieralised AI. Distinctive glassy incisors often result from FAM20A mutations. Gingival overgrowth is nearly always also seen. There are a variety of associated oral defects that may include delayed tooth eruption, hyperplastic dental follicles, pulp stones and gingival overgrowth with ectopic calcification. Calcification of other organs, most frequently nephrocalcinosis, is variably reported. This may be due to a combination of age, genetic modifiers, and exposure to Ca2+ channel blocking drugs. Monitoring of kidney function throughout life is necessary. Majority of mutations identified to date are nonsense, frameshift or splicing variants, but missense mutations have also been identified. FAM20A accounts for around 15% of the AI cases reported to date. See FAM20A LOVD: http://dna2.leeds.ac.uk/LOVD/genes/FAM20A

Created: 2 Aug 2017, 3 p.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Amelogenesis imperfecta, type IG (enamel-renal syndrome) 204690

Publications

• PMID: 21990045
• 24756937
• 23697977
• 23434854
• 24259279
• 24196488
• 21549343
• 23468644
• 26502894
• 25827751

Comment when marking as ready: Marked as ready: August 16th 2017.

Created: 16 Aug 2017, 8:47 a.m.

Comment on list classification: Updated rating from Amber to Green: Green expert review and on the Leeds diagnostic panel. Plus confirmed AI gene in DD-G2P. Plus sufficient cases (>3) to support causation.

Created: 16 Aug 2017, 8:47 a.m.

Comment on mode of inheritance: Biallelic MOI confirmed by OMIM and G2P.

Created: 8 Jun 2017, 10:05 a.m.

Confirmed DD-G2P gene for MIM:204690.

Created: 8 Jun 2017, 10:05 a.m.