1. Prevalence of DDC genotypes in patients with aromatic L-amino acid decarboxylase (AADC) deficiency and in silico prediction of structural protein changes
- Author
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ÖZTÜRK HİŞMİ, BURCU and Himmelreich N., Bertoldi M., Alfadhel M., Alghamdi M. A., Anikster Y., Bao X., Bashiri F. A., Zeev B. B., Bisello G., Ceylan A. C., et al.
- Subjects
Internal Diseases ,Serotonin ,GENETİK VE KALITIM ,ENDOCRINOLOGY & METABOLISM ,Endocrinology, Diabetes and Metabolism ,Dopamine ,Endocrinology and Metabolic Diseases ,Life Sciences (LIFE) ,Molecular Biology and Genetics ,Sağlık Bilimleri ,Endokrinoloji ,Biochemistry ,İç Hastalıkları ,Clinical Medicine (MED) ,Tıbbi Genetik ,Endocrinology ,BİYOKİMYA VE MOLEKÜLER BİYOLOJİ ,Biyokimya ,Yaşam Bilimleri ,Health Sciences ,Genetics ,Klinik Tıp (MED) ,Cytogenetic ,Genetik ,GENETICS & HEREDITY ,Molecular Biology ,Moleküler Biyoloji ve Genetik ,Variant effect prediction ,Internal Medicine Sciences ,Klinik Tıp ,Moleküler Biyoloji ,Temel Bilimler ,Life Sciences ,Dahili Tıp Bilimleri ,CLINICAL MEDICINE ,Tıp ,MOLECULAR BIOLOGY & GENETICS ,Neurotransmitter disorder ,Yaşam Bilimleri (LIFE) ,ACMG ,Endokrinoloji ve Metabolizma Hastalıkları ,ENDOKRİNOLOJİ VE METABOLİZMA ,Medicine ,Endokrinoloji, Diyabet ve Metabolizma ,Natural Sciences ,Medical Genetics ,BIOCHEMISTRY & MOLECULAR BIOLOGY ,Sitogenetik - Abstract
Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive genetic disorder affecting the biosynthesis of dopamine, a precursor of both norepinephrine and epinephrine, and serotonin. Diagnosis is based on the analysis of CSF or plasma metabolites, AADC activity in plasma and genetic testing for variants in the DDC gene. The exact prevalence of AADC deficiency, the number of patients, and the variant and genotype prevalence are not known. Here, we present the DDC variant (n = 143) and genotype (n = 151) prevalence of 348 patients with AADC deficiency, 121 of whom were previously not reported. In addition, we report 26 new DDC variants, classify them according to the ACMG/AMP/ACGS recommendations for pathogenicity and score them based on the predicted structural effect. The splice variant c.714+4A>T, with a founder effect in Taiwan and China, was the most common variant (allele frequency = 32.4%), and c.[714+4A>T];[714+4A>T] was the most common genotype (genotype frequency = 21.3%). Approximately 90% of genotypes had variants classified as pathogenic or likely pathogenic, while 7% had one VUS allele and 3% had two VUS alleles. Only one benign variant was reported. Homozygous and compound heterozygous genotypes were interpreted in terms of AADC protein and categorized as: i) devoid of full-length AADC, ii) bearing one type of AADC homodimeric variant or iii) producing an AADC protein population composed of two homodimeric and one heterodimeric variant. Based on structural features, a score was attributed for all homodimers, and a tentative prediction was advanced for the heterodimer. Almost all AADC protein variants were pathogenic or likely pathogenic.
- Published
- 2023