Exome sequencing reveals predominantly de novo variants in disorders with intellectual disability (ID) in the founder population of Finland
Schrauwen Isabelle; Leppälä Juha; Linnankivi Tarja; Nouel-Saied Liz M.; Kälviäinen Reetta; Leal Suzanne M.; Acharya Anushree; Jolly Angad; Olme Jan; Arvio Maria; Järvelä Irma; Llaci Lorida; Kokkonen Hannaleena; Cornejo-Sanchez Diana M.; Kankuri-Tammilehto Minna; Varilo Teppo; Posey Jennifer E.; Palomäki Maarit; Jhangiani Shalini N.; Lupski James R.; Paetau Ritva; Saarela Anni; Hadley Trevor D.; Fang Mary; Määttä Tuomo; Siren Auli
Exome sequencing reveals predominantly de novo variants in disorders with intellectual disability (ID) in the founder population of Finland
Schrauwen Isabelle
Leppälä Juha
Linnankivi Tarja
Nouel-Saied Liz M.
Kälviäinen Reetta
Leal Suzanne M.
Acharya Anushree
Jolly Angad
Olme Jan
Arvio Maria
Järvelä Irma
Llaci Lorida
Kokkonen Hannaleena
Cornejo-Sanchez Diana M.
Kankuri-Tammilehto Minna
Varilo Teppo
Posey Jennifer E.
Palomäki Maarit
Jhangiani Shalini N.
Lupski James R.
Paetau Ritva
Saarela Anni
Hadley Trevor D.
Fang Mary
Määttä Tuomo
Siren Auli
SPRINGER
Julkaisun pysyvä osoite on:
https://urn.fi/URN:NBN:fi-fe2021042826093
https://urn.fi/URN:NBN:fi-fe2021042826093
Tiivistelmä
The genetics of autosomal recessive intellectual disability (ARID) has mainly been studied in consanguineous families, however, founder populations may also be of interest to study intellectual disability (ID) and the contribution of ARID. Here, we used a genotype-driven approach to study the genetic landscape of ID in the founder population of Finland. A total of 39 families with syndromic and non-syndromic ID were analyzed using exome sequencing, which revealed a variant in a known ID gene in 27 families. Notably, 75% of these variants in known ID genes were de novo or suspected de novo (64% autosomal dominant; 11% X-linked) and 25% were inherited (14% autosomal recessive; 7% X-linked; and 4% autosomal dominant). A dual molecular diagnosis was suggested in two families (5%). Via additional analysis and molecular testing, we identified three cases with an abnormal molecular karyotype, including chr21q22.12q22.2 uniparental disomy with a mosaic interstitial 2.7 Mb deletion covering DYRK1A and KCNJ6. Overall, a pathogenic or likely pathogenic variant was identified in 64% (25/39) of the families. Last, we report an alternate inheritance model for 3 known ID genes (UBA7, DDX47, DHX58) and discuss potential candidate genes for ID, including SYPL1 and ERGIC3 with homozygous founder variants and de novo variants in POLR2F and DNAH3. In summary, similar to other European populations, de novo variants were the most common variants underlying ID in the studied Finnish population, with limited contribution of ARID to ID etiology, though mainly driven by founder and potential founder variation in the latter case.
Kokoelmat
- Rinnakkaistallenteet [19207]