Sophia K Krutzke1, Hartmut Engels1, Andrea Hofmann1,2, Madita M Schumann1, Kirsten Cremer1, Alexander M Zink1, Alina Hilger1, Michael Ludwig3, Ulrich Gembruch4, Heiko Reutter1,5, Waltraut M Merz4. 1. Institute of Human Genetics, University of Bonn, Bonn, Germany. 2. Department of Genomics, Life and Brain Center, University of Bonn, Bonn, Germany. 3. Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany. 4. Department of Obstetrics and Prenatal Medicine, University of Bonn, Bonn, Germany. 5. Department of Neonatology and Pediatric Intensive Care, Children's Hospital, University of Bonn, Bonn, Germany.
Abstract
BACKGROUND: For the majority of congenital brain malformations, the underlying cause remains unknown. Recent studies have implicated rare copy number variations (CNVs) in their etiology. METHODS: Here, we used array-based molecular karyotyping to search for causative CNVs in 33 fetuses of terminated pregnancies with prenatally detected brain malformations and additional extracerebral anomalies. RESULTS: In 11 fetuses, we identified 15 CNVs (0.08 Mb to 29.59 Mb), comprising four duplications and eleven deletions. All larger CNVs (> 5 Mb) had also been detected by prenatal conventional karyotyping. None of these CNVs was present in our 1307 healthy in-house controls (frequency < 0.0008). Among these CNVs, we prioritized six chromosomal regions (1q25.1, 5q35.1, 6q25.3-qter, 11p14.3, 15q11.2-q13.1, 18q21.1) due to their previous association with human brain malformations or owing to the presence of a single gene expressed in human brain. Prioritized genes within these regions were UBTD2, SKA1, SVIP, and, most convincingly, GPR52. However, re-sequencing of GPR52 in 100 samples from fetuses with brain malformations or patients with intellectual disability and brain malformations revealed no disease-causing mutation. CONCLUSION: Our study suggests chromosomal regions 1q25.1, 5q35.1, 6q25.3-qter, 11p14.3, 15q11.2-q13.1, and 18q21.1 to be involved in human brain development. Within three of these regions, we suggest UBTD2, GPR52, and SKA1 as possible candidate genes. Because the overall detection rate of array-based molecular karyotyping was slightly higher (23%) than that of conventional prenatal karyotyping (20%), we suggest it's use for prenatal diagnostic testing in fetuses with nonisolated brain malformations.
BACKGROUND: For the majority of congenital brain malformations, the underlying cause remains unknown. Recent studies have implicated rare copy number variations (CNVs) in their etiology. METHODS: Here, we used array-based molecular karyotyping to search for causative CNVs in 33 fetuses of terminated pregnancies with prenatally detected brain malformations and additional extracerebral anomalies. RESULTS: In 11 fetuses, we identified 15 CNVs (0.08 Mb to 29.59 Mb), comprising four duplications and eleven deletions. All larger CNVs (> 5 Mb) had also been detected by prenatal conventional karyotyping. None of these CNVs was present in our 1307 healthy in-house controls (frequency < 0.0008). Among these CNVs, we prioritized six chromosomal regions (1q25.1, 5q35.1, 6q25.3-qter, 11p14.3, 15q11.2-q13.1, 18q21.1) due to their previous association with humanbrain malformations or owing to the presence of a single gene expressed in human brain. Prioritized genes within these regions were UBTD2, SKA1, SVIP, and, most convincingly, GPR52. However, re-sequencing of GPR52 in 100 samples from fetuses with brain malformations or patients with intellectual disability and brain malformations revealed no disease-causing mutation. CONCLUSION: Our study suggests chromosomal regions 1q25.1, 5q35.1, 6q25.3-qter, 11p14.3, 15q11.2-q13.1, and 18q21.1 to be involved in human brain development. Within three of these regions, we suggest UBTD2, GPR52, and SKA1 as possible candidate genes. Because the overall detection rate of array-based molecular karyotyping was slightly higher (23%) than that of conventional prenatal karyotyping (20%), we suggest it's use for prenatal diagnostic testing in fetuses with nonisolated brain malformations.
Authors: Esaú Floriano-Sánchez; Fernando Brindis; Daniel Ortega-Cuellar; Ivan Ignacio-Mejía; Elizabeth Moreno-Arriola; Pablo Romero-Morelos; Edgar Ceballos-Vasquez; María Guadalupe Córdova-Espinoza; Cindy Karel Arregoitia-Sarabia; Roberto Sandoval-Pacheco; Liliana Carmona-Aparicio; Noemí Cárdenas-Rodríguez Journal: Genes (Basel) Date: 2018-06-28 Impact factor: 4.096