eprintid: 10100491 rev_number: 8 eprint_status: archive userid: 695 dir: disk0/10/10/04/91 datestamp: 2020-06-11 09:03:35 lastmod: 2020-06-11 09:03:35 status_changed: 2020-06-11 09:03:35 type: thesis metadata_visibility: show creators_name: Goulding, Jonathan N. title: A study on the localisation of the PHEX gene, and mutation analysis of patients with X-linked hypophosphataemic rickets ispublished: unpub keywords: Biological sciences; Rickets note: Thesis digitised by ProQuest. abstract: X-linked hypophosphataemic rickets (HYP) is an X-linked dominant disorder that affects 1 in 20000 live births. The disease is characterised by a failure of the kidney to reabsorb phosphate from the glomerular filtrate, resulting in a phosphate leak and hypophosphataemia. The disease had previously been localised to the Xp22.1-22.2 region of the X chromosome, flanked by polymorphic markers DXS43andDXS41. Twenty affected kindreds were screened with an additional eleven polymorphic markers, which localised the gene to a 200-300 kb region in Xp22.1, which lay on a single YAC, A0472. To further order the markers a YAC and cosmid contig from the region were also screened with these markers, with the following marker order deemed the most likely: Xptel - DXS43 - DXS197 - DXS999 - DXS443 - (DXS365, DXS7475, DXS7101) -DXS7474 - DXS7473 - HYP - DXS1683 - DXS1052 - DXS274 - DXS41 - Xcen. Screening Southern blots of patient DNA with cosmids that overlapped YAC A0472, identified a cosmid that showed an altered banding pattern, and therefore a mutation, in two unrelated individuals. This cosmid was sequenced and a candidate gene (PHEX) identified. The gene showed homology at the amino acid level to a family of metalloendopeptidases. To confirm that PHEX was the gene involved in X-linked hypophosphataemic rickets, patient DNA from eighty unrelated families was screened by Single Stranded Conformational Polymorphism (SSCP). A total of twenty three different mutations were identified, which included both deletions and point mutations. This confirmed that PHEX was the gene involved in the HYP disorder. date: 2001 oa_status: green full_text_type: other thesis_class: doctoral_open thesis_award: Ph.D language: eng thesis_view: UCL_Thesis primo: open primo_central: open_green verified: verified_manual full_text_status: public pages: 259 institution: UCL (University College London) thesis_type: Doctoral citation: Goulding, Jonathan N.; (2001) A study on the localisation of the PHEX gene, and mutation analysis of patients with X-linked hypophosphataemic rickets. Doctoral thesis (Ph.D), UCL (University College London). Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10100491/1/out.pdf