Early onset or syndromic epilepsy

Gene: DDC

The rating of this gene has been updated following NHS Genomic Medicine Service approval.

Created: 3 Mar 2022, 5:34 p.m. | Last Modified: 3 Mar 2022, 5:34 p.m.

Panel Version: 2.491

Comment on list classification: This is a metabolic gene and is green on the Inborn errors of metabolism (https://panelapp.genomicsengland.co.uk/panels/467/gene/DDC/) therefore it is rated as amber on the Genetic epilepsy syndromes panel.

Created: 25 Aug 2020, 10:19 a.m. | Last Modified: 25 Aug 2020, 10:19 a.m.

Panel Version: 2.144

Green List (high evidence)

Seizures are not a key symptom for aromatic L-amino acid decarboxylase deficiency (AADCD). However, some patients have seizures. Oculogyric crises, which are a key symptom, could be mistaken for epileptic seizures. In the review paper of Wassenberg et al. (2017) about 8% of AADCD patients suffer from seizures (9/117). Manegold et al. (2009) found 3 patients with seizures and corresponding EEG abnormalities in a cohort of 9 patients. They also point out, that it was difficult to discriminate seizures from oculogyric crises and paroxysmal dystonia. Another review by Brun et al. (2010) mentions abnormal EEG in 10 out of 78 patients without further detail about seizures. In recent cohort analysis they concluded that about 30% of AADCD patients have been initially diagnosed with epilepsy (Pearson et al.2020, Wen et al. 2020)
Sources: Literature

Update: Added more literature

Created: 25 Feb 2020, 1:19 p.m. | Last Modified: 19 Jun 2020, 11:02 a.m.

Panel Version: 2.93

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Aromatic L-amino acid decarboxylase deficiency 608643; floppy child; dystonia; hypotonia; developmental delay; oculogyric crisis

Publications

• 28100251
• 30952622
• 20505134
• 19172410
• 32369189
• 18754761
• 32409695