Dekker Jordy, Schot Rachel, Aldinger Kimberly A, Everman David B, Washington Camerun, Jones Julie R, Sullivan Jennifer A, Spillmann Rebecca C, Shashi Vandana, Vitobello Antonio, Denommé-Pichon Anne-Sophie, Mosca-Boidron Anne-Laure, Perrin Laurence, Auvin Stéphane, Zaki Maha S, Gleeson Joseph G, Meave Naomi, Wallace Cassidy, Nambot Sophie, Delanne Julian, Ruggiero Sarah M, Helbig Ingo, Fitzgerald Mark P, Leventer Richard J, Grange Dorothy K, Argilli Emanuela, Sherr Elliott H, Prakash Supraja, Neilson Derek E, Nicita Francesco, Sferra Antonella, Bertini Enrico S, Aiello Chiara, Brockmann Knut, Kuranov Alexander B, Kaulfuss Silke, Basit Sulman, Alluqmani Majed, Almatrafi Ahmad, Friedman Jan M, Guimond Colleen, Mohammed Faruq, Sharma Pooja, Goel Divya, Wirth Thomas, Anheim Mathieu, Bahena Paulina, Koparir Asuman, Kolokotronis Konstantinos, Vona Barbara, Haaf Thomas, Kunstmann Erdmute, Maroofian Reza, Sczakiel Henrike L, Boschann Felix, Misra-Isrie Mala, Louie Raymond J, Stolerman Elliot S, Sanchez-Lara Pedro A, Mergler Sandra, Oegema Renske, Zarate Yuri A, Kariminejad Ariana, Tajsharghi Homa, Zeidler Shimriet, Kievit Anneke J A, Bouman Arjan, Cappuccio Gerarda, Brunetti-Pierri Nicola, Stuurman Kyra E, Swols Dayna Morel, Tekin Mustafa, Upadia Jariya, Martin Donna M, Craven Daniel, Hiatt Susan M, van de Pol Laura A, D'Arco Felice, Margot Henri, Wilke Martina, Yousefi Soheil, Barakat Tahsin Stefan, van Veghel-Plandsoen Monique M, Aronica Eleonora, Anink Jasper, Rogers Stephen L, Slep Kevin C, Doherty Dan, Dobyns William B, Mancini Grazia M S
Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, Rotterdam 3000 CA, the Netherlands.
Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, Rotterdam 3000 CA, the Netherlands; Discovery Unit, Department of Clinical Genetics, Erasmus MC University Medical Center Rotterdam, PO Box 2040, Rotterdam 3000 CA, the Netherlands.
Am J Hum Genet. 2025 Sep 3. doi: 10.1016/j.ajhg.2025.08.010.
Microtubule-actin cross-linking factor 1 (MACF1) is a large protein of the spectraplakin family, which is essential for brain development. MACF1 interacts with microtubules through the growth arrest-specific 2 (Gas2)-related (GAR) domain. Heterozygous MACF1 missense variants affecting the zinc-binding residues in this domain result in a distinctive cortical and brain stem malformation. Evidence for other MACF1-associated disorders is still limited. Here, we present a cohort of 45 individuals with heterozygous or bi-allelic MACF1 variants to explore the phenotypic spectrum and assess possible pathogenic relevance. We observe that de novo heterozygous missense variants in the EF-hand domains also result in distinctive brain malformation and provide experimental evidence that variants in the EF-hand/GAR module increase microtubule binding, suggestive of a toxic gain of function. Notably, no phenotype-genotype correlation was possible for the remaining heterozygous variants in other domains. A clinical review of eight families with bi-allelic variants reveals a possible complex neurodevelopmental syndrome of the central and peripheral nervous systems. In these individuals, bi-allelic variants mostly affect the Plakin domain. Furthermore, RNA sequencing and chromatin immunoprecipitation (ChIP) analyses of human fetal brain tissue reveal five MACF1 isoforms with region-specific expression, differing in their exon 1 transcription start sites but splicing to a common exon 2. This differential expression explains the frontal-predominant lissencephaly in an individual with a homozygous stop-gain in exon 1 (MACF1-204: c.70C>T [p.Arg24∗]), as this isoform is preferentially expressed in the frontal cortex. We conclude that MACF1-related disorders are strictly linked to domain function and the level of transcript expression, explaining the observed wide clinical heterogeneity.
微管-肌动蛋白交联因子1（MACF1）是光谱斑蛋白家族的一种大型蛋白质，对大脑发育至关重要。MACF1通过生长停滞特异性2（Gas2）相关（GAR）结构域与微管相互作用。影响该结构域中锌结合残基的杂合MACF1错义变体导致独特的皮质和脑干畸形。其他与MACF1相关疾病的证据仍然有限。在这里，我们展示了一组45名携带杂合或双等位基因MACF1变体的个体，以探索表型谱并评估可能的致病相关性。我们观察到EF手结构域中的新生杂合错义变体也会导致独特的脑畸形，并提供实验证据表明EF手/GAR模块中的变体增加了微管结合，提示功能获得性毒性。值得注意的是，其他结构域中其余的杂合变体不存在表型-基因型相关性。对八个具有双等位基因变体的家族进行的临床回顾揭示了一种可能的中枢和外周神经系统复杂神经发育综合征。在这些个体中，双等位基因变体大多影响Plakin结构域。此外，对人类胎儿脑组织的RNA测序和染色质免疫沉淀（ChIP）分析揭示了五种具有区域特异性表达的MACF1同工型，它们的外显子1转录起始位点不同，但剪接到共同的外显子2。这种差异表达解释了一名外显子1纯合终止获得（MACF1-204：c.70C>T [p.Arg24∗]）个体中以额叶为主的无脑回畸形，因为这种同工型在额叶皮质中优先表达。我们得出结论，MACF1相关疾病与结构域功能和转录本表达水平密切相关，解释了观察到的广泛临床异质性。
