Klinična in genetska raziskava bolnikov z edemom goleni in sindaktilijo prstov nog

doktorska disertacija

Tanja Planinšek Ručigaj (Author), Jovan Miljković (Mentor), Ivan Krajnc (Thesis defence commission member), Peter Korošec (Co-mentor)

Abstract

Limfedem, periferni zastoj beljakovinsko bogate intersticijske tekočine v tkivu, nastane zaradi motenj v transportu limfne tekočine. Kaže se kot otekanje udov ali drugih delov telesa. Motnje v transportu limfne tekočine so lahko posledica presežka intersticijske limfne tekočine ali nepravilnega delovanje limfnega sistema. Slednje je v razvitem svetu v večji meri posledica zdravljenja rakavih obolenj (sekundarni limfedem), v manjšem deležu pa se pri bolnikih razvije primarni limfedem, ki je prisoten že ob rojstvu ali se pojavi kasneje v življenju. Primarni limfedemi lahko nastanejo zaradi dednih genetskih mutacij (okrog 10 % primarnih limfedemov), medtem ko je približno 90 % motenj v razvoju limfnega sistema (limfnega žilja ali bezgavk) posledica sporadičnih mutacij. Poleg tega podatki iz literature nakazujejo na možno genetsko ozadje tudi pri bolnikih z edemom goleni in kožno sindaktilijo baze II. in III. nožnega prsta. Nezdravljen ali prepozno zdravljen limfedem privede do napredujočega slabšanja otekline, številnih zapletov in slabše kvalitete življenja bolnika. Z raziskavo smo želeli opredeliti genetsko ozadje slovenskih bolnikov z dednim primarnim limfedemom. Genetsko analizo smo želeli opraviti tudi pri skupini bolnikov s kožno sindaktilijo baze II. in III. prsta na nogi in otekanjem goleni. V raziskavo smo vključili pet slovenskih družin z znanim dednim primarnim limfedemom ter skupino 40 bolnikov z nepojasnjenim edemom goleni in kožno sindaktilijo baze II. in III. nožnega prsta. Po natančni klinični opredelitvi smo za genetsko analizo uporabili metodo sekvenciranja naslednje generacije in sekvenciranja po Sangerju. S sekvenciranjem smo opredelili prisotnost mutacij v 26 genih, ki jih povezujemo z nastankom primarnnega limfedema, in v 19 genih, ki jih povezujemo s sindaktilijo. V prvi slovenski raziskavi bolnikov z dednim primarnim limfedemom smo pri treh družinah potrdili genetsko ozadje bolezni. V Družini 1 smo našli novo, do sedaj neopisano mutacijo gena FOXC2, kjer smo dokazali heterozigotno vstavitev adenozina za citozinom na nukleotidnem mestu 867 (c.867_868insA). Ker odkrita mutacija ni bila predhodno opisana v literaturi, smo dodatno testirali 182 zdravih posameznikov (kontrole), pri katerih omenjene mutacije nismo dokazali. V Družini 2, v kateri ima vseh sedem otrok dedni primarni limfedem, kar nakazuje na dominantno avtosomno dedovanje, nismo našli nobene mutacije v katerem koli izmed 26 preiskovanih genov, povezanih z nastankom dednega primarnega limfedema. V Družinah 3 in 4 smo pri družinskih članih z dednim primarnim limfedemom obeh spodnjih udov odkrili mutacijo Pro1137Leu (c.3410C>T) v eksonu 25 gena FLT4, ki je bila predhodno že opisana v literaturi. Pri dveh družinskih članih Družine 5 smo dokazali mutacijo Leu394Met (c.1180C>A) v eksonu 12 gena TSC2. Naša bolnika z različico TSC2 se od ostalih bolnikov, opisanih v literaturi, razlikujeta po tem, da nimata nobenih drugih kliničnih znakov tuberozne skleroze, ki je sicer povezana z mutacijami v TSC. V skupini bolnikov z edemom goleni in kožno sindaktilijo baze II.-III. prsta nog nismo potrdili povezave med genetskimi variantami in limfedemom ali sindaktilijo. V doktorski disertaciji smo prvič genetsko opredelili slovenske bolnike z dednim primarnim limfedemom. Odkrili smo novo, v literaturi do sedaj še neopisano mutacijo v genu FOXC2, ter potrdili mutacije v genih FLT4 in TSC2. Pri družinah z dednim primarnim limfedemom, pri katerih nismo našli nobene mutacije v najpomembnejših genih, bodo potrebne nadaljnje raziskave za potrditev genetskega ozadja nastanka limfedemov. Opredelitev mutacij pri teh bolnikih je pomembna zaradi genetskega svetovanja mladim bolnikom pri načrtovanju družine, za svetovanje glede načina življenja, načrtovanja posamezniku prilagojene terapije, zaradi preprečevanja slabšanja edema ter pojava neželenih zapletov, do katerih lahko privede prepozno ali nepravilno zdravljenje in zagotavljanja boljše kvalitete življenja.

Keywords

prirojeni limfedem;nožni prsti;kožna sindaktilija;noga;otekanje;sekvenciranje;mutacije;Bolezni gibal;Disertacije;Golen;Sindaktilija;Primarni limfedem;Genetika;Bolezni limfnega sistema;Limfedemi;

Data

Language:	Slovenian
Year of publishing:	2018
Typology:	2.08 - Doctoral Dissertation
Organization:	UM MF - Faculty of Medicine
Publisher:	T. Planinšek Ručigaj]
UDC:	616.42-005.98:577.21(043.3)
COBISS:	297302528
Views:	1242
Downloads:	94
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	CLINICAL AND GENETIC RESEARCH OF PATIENTS WITH SWELLING LEGS AND SYNDACTYLY OF THE TOES
Secondary abstract:	Lymphoedema, disorder in the transport of lymphatic fluid can be hindered due to an excess of interstitial fluid or failure of the lymphatic system. Impairment of the lymphatic drainage is mostly caused by cancer/its treatment. Patients can also have hereditary primary lymphoedema, which may already be present at birth or develop later. In approximately 10% of cases, congenital primary lymphoedema develops due to hereditary genetic disorders in lymph vessels/lymph nodes, or in 90% occur due to sporadic mutations. Limited data in the literature indicate a possible genetic background in patients with oedema on the shin and skin syndactyly on the base of II. and III. toes. The purpose of doctoral dissertation was to define the genetic background of Slovenian patients with hereditary primary lymphoedema. Genetic analysis was also performed in the group of patients with leg swelling and skin syndactyly on the base of II. and III. toes. The study included five Slovenian families with previously diagnosed hereditary primary lymphoedema. In addition, 40 patients with unexplained oedema on the shine and skin syndactyly on the base of II. and III. toes were included. Following clinical examination, sequence analysis of genes associated with primary lymphoedema and/or syndactyly was performed using next generation sequencing and Sanger sequencing. We analysed a total of 26 and 19 genes associated with primary lymphoedema and syndactyly. This is the first Slovenian study on patients with hereditary primary lymphoedema. The genetic background of the disease was confirmed in three out of five families. In the first family, we identified a novel, previously undescribed mutation within the FOXC2 gene with heterozygous insertion of adenosine after cytosine at nucleotide position 868(c.867_868insA). This mutation has not been previously described in the literature, so we further tested a total of 182 healthy individuals but were unable to identify it in this group of controls. Autosomal dominant inheritance was most likely implicated in the second family, since all 7 children had hereditary primary lymphoedema. We did not detect any known or unknown genetic variants within the 26 genes that are associated with hereditary primary lymphoedema. In the third and fourth family with hereditary primary lymphoedema that manifested on both feet, we found the Pro1137Leu mutation (c.3410C>T) in exon 25 within the FLT4 gene, which was already described in the literature. In the case of two family members of the fifth family with hereditary primary lymphoedema, the Leu394Met (c.1180C>A) mutation in the exon 12 within the TSC2 gene was found. Our patients with the TSC2 mutation differ from those described in the literature, as they did not exhibit other clinical signs or symptoms of tuberous sclerosis, which is otherwise associated with the TSC gene mutations. In the group of patients with oedema and skin syndactyly on the base of II. and III. toes, we did not find any lymphoedema- or syndactyly-associated genetic mutations. In this study, we defined for the first time genetic background in Slovenian patients with hereditary primary lymphoedema. We identified a novel, previously unpublished mutation within the FOXC2 gene, and confirmed the presence of mutations within the FLT4 and TSC2 genes in Slovenian patients with hereditary primary lymphoedema. Further studies are needed on families with hereditary primary lymphoedema that did not harbour any identifiable genetic mutations. Identification of genetic mutations in patients with primary hereditary lymphoedema is especially important because genetic counselling can be provided to young patients in case of family planning, for advised regarding the lifestyle changes, to adjust therapy for each individual to prevent worsening of oedema and development of unwanted complications and to improve the quality of life.
Secondary keywords:	hereditary primary lymphoedema;leg swelling;toes syndactyly;genetic analysis;FOXC2 mutation;FLT4 mutation;TSC2 mutation;
URN:	URN:SI:UM:
Type (COBISS):	Dissertation
Thesis comment:	Univ. v Mariboru, Medicinska fak.
Pages:	180 str.
ID:	10921451