Identification of 1q21.1 microduplication in a family: A case report

Table 1 Genes contained in the 1.58 Mb duplication region and their functions

Gene	Phenotype	Inheritance	Gene function
GJA5	Atrial Fibrillation, Familial, 11; Atrial Standstill 1; Tetralogy of Fallot; Chromosome 1q21.1 deletion syndrome, 1.35-MB	AD	The GJA5 gene encodes gap junction protein 40 (CX40), a cardiac gap junction protein expressed in the right ventricular outflow tract, which plays a key role in cell adhesion and intercellular communication
FMO5	Duodenal Atresia; Jacobsen Syndrome; Mowat-Wilson Syndrome	AD	The gene acts as Baeyer-Villiger monooxygenase on a broad range of substrates. Catalyzes the insertion of an oxygen atom into a carbon-carbon bond adjacent to a carbonyl, which converts ketones to esters
CHD1L	Postcholecystectomy Syndrome; Prostate Calculus; Chromosome 1q21.1 Duplication Syndrome	AD	DNA helicase which plays a role in chromatin-remodeling following DNA damage, targeted to sites of DNA damage through interaction with poly (ADP-ribose) and functions to regulate chromatin during DNA repair. Able to catalyze nucleosome sliding in an ATP-dependent manner. Helicase activity is strongly stimulated upon poly (ADP-ribose)-binding
NBPF12	Amelogenesis Imperfecta, Type Ia; Neuroblastoma; Microcephaly; Autism	Unknown	No data available for molecular function
NBPF11	Neuroblastoma; Duodenal Atresia	Unknown	Predicted to be located in the cytoplasm. No data available for molecular function
NBPF24	Also known asNBPF11	Unknown	No data available for molecular function
PRKAB2	Chromosome 1q21.1 Duplication Syndrome; Type 2 Diabetes Mellitus	Unknown	Non-catalytic subunit of AMP-activated protein kinase (AMPK), an energy sensor protein kinase that plays a key role in regulating cellular energy metabolism
BCL9	Chromosome 1q21.1 Duplication Syndrome; Lymphoma; Leukemia; Retinitis Pigmentosa	Unknown	Involved in signal transduction through the Wnt pathway. Promotes beta-catenin's transcriptional activity. Gene coding for a large proline-rich protein with two transcripts, expressed in all tissues and a third expressed only in thymus, spleen, small intestine, involved in translocation t(1;14) and t(1;22)
GJA8	Chromosome 1q21.1 Duplication Syndrome; Cataract 1, Multiple Types; Cataract Microcornea Syndrome; Early-Onset Sutural Cataract	AD	Structural component of eye lens gap junctions. Gap junctions are dodecameric channels that connect the cytoplasm of adjoining cells. They are formed by the docking of two hexameric hemichannels, one from each cell membrane. Small molecules and ions diffuse from one cell to a neighboring cell via the central pore
GPR89B	Thrombocytopenia-Absent Radius Syndrome; Hypothyroidism, Congenital, Nongoitrous, 1	Unknown	Voltage dependent anion channel required for acidification and functions of the Golgi apparatus that may function in counter-ion conductance. Plays a role in lymphocyte development, probably by acting as a RABL3 effector in hematopoietic cells
GPR89C	Also known as, GPR89B	Unknown	The function of the gene is the same as GPR89B

ADP: Adenosine diphosphate; AD: Autosomal dominant; AMP: Adenosine monophosphate; DNA: Deoxyribonucleic acid.