title: Dominant Splice Site Mutations in PIK3R1 Cause Hyper IgM Syndrome, Lymphadenopathy and Short Stature.
abstract: The purpose of this research was to use next generation sequencing to identify mutations in patients with primary immunodeficiency diseases whose pathogenic gene mutations had not been identified. Remarkably, four unrelated patients were found by next generation sequencing to have the same heterozygous mutation in an essential donor splice site of PIK3R1 (NM_181523.2:c.1425 + 1G > A) found in three prior reports. All four had the Hyper IgM syndrome, lymphadenopathy and short stature, and one also had SHORT syndrome. They were investigated with in vitro immune studies, RT-PCR, and immunoblotting studies of the mutation's effect on mTOR pathway signaling. All patients had very low percentages of memory B cells and class-switched memory B cells and reduced numbers of naïve CD4+ and CD8+ T cells. RT-PCR confirmed the presence of both an abnormal 273 base-pair (bp) size and a normal 399 bp size band in the patient and only the normal band was present in the parents. Following anti-CD40 stimulation, patient's EBV-B cells displayed higher levels of S6 phosphorylation (mTOR complex 1 dependent event), Akt phosphorylation at serine 473 (mTOR complex 2 dependent event), and Akt phosphorylation at threonine 308 (PI3K/PDK1 dependent event) than controls, suggesting elevated mTOR signaling downstream of CD40. These observations suggest that amino acids 435-474 in PIK3R1 are important for its stability and also its ability to restrain PI3K activity. Deletion of Exon 11 leads to constitutive activation of PI3K signaling. This is the first report of this mutation and immunologic abnormalities in SHORT syndrome.
authors.affiliation: Institute for Genomic Medicine, Columbia University, New York, NY, 10032, USA.
authors.forename: Slavé
authors.initials: S
authors.lastname: Petrovski
authors.affiliation: Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, 127 MSRB1, Box 2898, Durham, NC, 27710, USA.
authors.forename: Roberta E
authors.initials: RE
authors.lastname: Parrott
authors.affiliation: Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, 127 MSRB1, Box 2898, Durham, NC, 27710, USA.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Roberts
authors.affiliation: Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, 127 MSRB1, Box 2898, Durham, NC, 27710, USA.|Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, China.
authors.forename: Hongxiang
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, 127 MSRB1, Box 2898, Durham, NC, 27710, USA.
authors.forename: Jialong
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, 127 MSRB1, Box 2898, Durham, NC, 27710, USA.
authors.forename: Balachandra
authors.initials: B
authors.lastname: Gorentla
authors.affiliation: Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, 127 MSRB1, Box 2898, Durham, NC, 27710, USA.|Departments of Internal Medicine and Pediatrics, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
authors.forename: Talal
authors.initials: T
authors.lastname: Mousallem
authors.affiliation: Department of Pathology, Duke University Medical Center, Durham, NC, 27710, USA.
authors.forename: Endi
authors.initials: E
authors.lastname: Wang
authors.affiliation: UCB NewMedicines, Slough, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Armstrong
authors.affiliation: UCB NewMedicines, Slough, UK.
authors.forename: Duncan
authors.initials: D
authors.lastname: McHale
authors.affiliation: Department of Pediatrics, Division of Endocrinology, Duke University Medical Center, Durham, NC, 27710, USA.|Department of Immunology, Duke University Medical Center, Durham, NC, 27710, USA.
authors.forename: Nancie J
authors.initials: NJ
authors.lastname: MacIver
authors.affiliation: Institute for Genomic Medicine, Columbia University, New York, NY, 10032, USA.
authors.forename: David B
authors.initials: DB
authors.lastname: Goldstein
authors.affiliation: Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, 127 MSRB1, Box 2898, Durham, NC, 27710, USA.|Department of Immunology, Duke University Medical Center, Durham, NC, 27710, USA.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Zhong
authors.affiliation: Department of Pediatrics, Division of Allergy and Immunology, Duke University Medical Center, 127 MSRB1, Box 2898, Durham, NC, 27710, USA. buckl003@mc.duke.edu.|Department of Immunology, Duke University Medical Center, Durham, NC, 27710, USA. buckl003@mc.duke.edu.
authors.forename: Rebecca H
authors.initials: RH
authors.lastname: Buckley
mesh_terms: D017398:Alternative Splicing / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology*; D002461:Cell Line, Transformed; D002648:Child; D002675:Child, Preschool; D058543:Class Ia Phosphatidylinositol 3-Kinase; D019465:Craniofacial Abnormalities; D004252:DNA Mutational Analysis; D004392:Dwarfism; D004423:Ear / Q000002:abnormalities; D005260:Female; D005799:Genes, Dominant; D006130:Growth Disorders / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D053306:Hyper-IgM Immunodeficiency Syndrome / Q000235:genetics*; D006934:Hypercalcemia / Q000235:genetics*; D000072281:Lymphadenopathy; D008297:Male; D008659:Metabolic Diseases / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D009333:Neck / Q000002:abnormalities; D009397:Nephrocalcinosis / Q000235:genetics*; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics*; D019893:Ribosomal Protein S6 Kinases / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D013909:Thorax / Q000002:abnormalities
chemical_list: D058543:Class Ia Phosphatidylinositol 3-Kinase; D019869:Phosphatidylinositol 3-Kinases; D019893:Ribosomal Protein S6 Kinases; D058570:TOR Serine-Threonine Kinases; C588001:PIK3R1 protein, human; C546842:MTOR protein, human
keywords: Hyper IgM syndrome; PIK3R1 splice site mutations; SHORT syndrome; lymphadenopathy; mTOR pathway; next generation sequencing; short stature