{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:03:03Z","timestamp":1760144583080,"version":"build-2065373602"},"reference-count":20,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2024,5,3]],"date-time":"2024-05-03T00:00:00Z","timestamp":1714694400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Science Centre in Poland","award":["UMO-2014\/15\/N\/NZ2\/00395"],"award-info":[{"award-number":["UMO-2014\/15\/N\/NZ2\/00395"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>The most common form of hereditary spastic paraplegia (HSP), SPG4 is caused by single nucleotide variants and microrearrangements in the SPAST gene. The high percentage of multi-exonic deletions or duplications observed in SPG4 patients is predisposed by the presence of a high frequency of Alu sequences in the gene sequence. In the present study, we analyzed DNA and RNA samples collected from patients with different microrearrangements in SPAST to map gene breakpoints and evaluate the mutation mechanism. The study group consisted of 69 individuals, including 50 SPG4 patients and 19 healthy relatives from 18 families. Affected family members from 17 families carried varying ranges of microrearrangements in the SPAST gene, while one individual had a single nucleotide variant in the 5\u2032UTR of SPAST. To detect the breakpoints of the SPAST gene, long-range PCR followed by sequencing was performed. The breakpoint sequence was detected for five different intragenic SPAST deletions and one duplication, revealing Alu-mediated microhomology at breakpoint junctions resulting from non-allelic homologous recombination in these patients. Furthermore, SPAST gene expression analysis was performed using patient RNA samples extracted from whole blood. Quantitative real-time PCR tests performed in 14 patients suggest no expression of transcripts with microrearrangements in 5 of them. The obtained data indicate that nonsense-mediated decay degradation is not the only mechanism of hereditary spastic paraplegia in patients with SPAST microrearrangements.<\/jats:p>","DOI":"10.3390\/ijms25095008","type":"journal-article","created":{"date-parts":[[2024,5,3]],"date-time":"2024-05-03T09:39:47Z","timestamp":1714729187000},"page":"5008","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["SPAST Intragenic CNVs Lead to Hereditary Spastic Paraplegia via a Haploinsufficiency Mechanism"],"prefix":"10.3390","volume":"25","author":[{"given":"Ewelina","family":"Elert-Dobkowska","sequence":"first","affiliation":[{"name":"Department of Genetics, Institute of Psychiatry and Neurology, 02-957 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Iwona","family":"Stepniak","sequence":"additional","affiliation":[{"name":"Department of Genetics, Institute of Psychiatry and Neurology, 02-957 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wiktoria","family":"Radziwonik-Fraczyk","sequence":"additional","affiliation":[{"name":"Department of Genetics, Institute of Psychiatry and Neurology, 02-957 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8318-0147","authenticated-orcid":false,"given":"Amir","family":"Jahic","sequence":"additional","affiliation":[{"name":"Institute of Diagnostic Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charit\u00e9\u2013Universit\u00e4tsmedizin, 10117 Berlin, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7061-2895","authenticated-orcid":false,"given":"Christian","family":"Beetz","sequence":"additional","affiliation":[{"name":"Department of Chemistry and Laboratory Medicine, Jena University Hospital, 07747 Jena, Germany"},{"name":"Centogene, 18055 Rostock, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2975-4888","authenticated-orcid":false,"given":"Anna","family":"Sulek","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Lazarski University, 02-662 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,5,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1016\/j.expneurol.2014.06.011","article-title":"Hereditary spastic paraplegia: Clinical-genetic characteristics and evolving molecular mechanisms","volume":"261","author":"Lombardi","year":"2014","journal-title":"Exp. 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