Identification of a de novo microdeletion 1q44 in a patient with hypogenesis of the corpus callosum, seizures and microcephaly - A case report.
Microdeletion 1q44 on the long arm of chromosome 1 leads to a phenotype that includes microcephaly, seizure, agenesis or hypogenesis of the corpus callosum, polydactyly, congenital heart defects and severe developmental delay along with characteristic facial dysmorphic signs. Until today, the distinct genetic causes for the different symptoms remain unclear. We here report a 1.2Mb de novo microdeletion 1q44 identified by performing a SNP array analysis. The female patient presented with microcephaly, seizure, hypogenesis of corpus callosum, postaxial hexadactyly, an atrial septal defect, a ventricular septal defect, hypertelorism, a long and smooth philtrum, thin vermilion borders, and micrognathia, all common features of microdeletion 1q44. An additionally performed chromosome analysis excluded any chromosomal rearrangements. The deleted region included the genes ZBTB18 as well as HNRNPU amongst others. Both are possibly candidate genes for the dysgenesis of the corpus callosum. AKT3, another candidate gene, was not affected by the deletion in this patient. Thus, the genetic findings in this case report spotlight ZBTB18 and HNRNPU in the genesis of the typical microdeletion 1q44 symptoms, especially concerning the dysgenesis of the corpus callosum, and therefore could help to unveil more of the genetic background of this syndrome.
Institute of Human Genetics, Technical University Munich, Munich, Germany; Institute of Human Genetics, Helmholtz Zentrum Munich, Neuherberg, Germany. Electronic address: dominik.westphal@mri.tum.de.
Dominik S
DS
Westphal
Institute of Human Genetics, Technical University Munich, Munich, Germany.
Stephanie
S
Andres
Department of Diagnostic and Pediatric Radiology, Schwabing Hospital, Munich, Germany.
Kirsten I
KI
Beitzel
Department for Pediatrics, Technical University Munich, Munich, Germany.
Christine
C
Makowski
Institute of Human Genetics, Technical University Munich, Munich, Germany; Institute of Human Genetics, Helmholtz Zentrum Munich, Neuherberg, Germany.
Thomas
T
Meitinger
Institute of Human Genetics, Technical University Munich, Munich, Germany.
Julia
J
Hoefele
D061085:Agenesis of Corpus Callosum / Q000235:genetics*; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D008831:Microcephaly / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D020641:Polymorphism, Single Nucleotide; D012097:Repressor Proteins / Q000235:genetics; D012640:Seizures / Q000235:genetics*; D017384:Sequence Deletion
D012097:Repressor Proteins; C115048:ZBTB18 protein, human
1q44 deletion; Hypogenesis of corpus callosum; Intellectual disability; Seizure