Handedness in schizophrenia and schizoaffective disorder in an afrikaner founder population

Abstract

Objective: An association between the Leucine-rich repeat trans membrane neuronal 1 gene (LRRTM1), schizophrenia/ schizoaffective disorder and handedness was recently claimed to be established. This study aimed to test the hypothesis that Afrikaner patients with schizophrenia/schizoaffective disorder are more non-right handed than their non-affected firstdegree relatives and that of two separate control groups. The association between handedness, gender and age at onset of illness in the patients group was also determined. Method: Two cross-sectional studies were carried out, which compared the handedness of a group of 100 (30 females and 70 males) Afrikaner patients with schizophrenia/schizoaffective disorder, their non-affected first-degree relatives, and two separate control groups. Handedness was determined by the Edinburg Handedness Inventory (EHI). Results: Patients were found to be more right-handed than expected with only 17 out of 100 being non-right-handed compared to 11 out of 100 non-affected relatives; 36 out of 100 students and 75 out of 500 nonaffected Afrikaner participants. The students were significantly more non-right handed than the patient and family groups but no difference in handedness was found when comparing the patients, family members and 500 participant control group. There was no significant difference between age at onset of illness and handedness. A significant association between female gender and non-right handedness in the patient group was found but no gender difference in the family and student groups. A highly significant association was found between the male gender of the patients and student control group regarding handedness. A significant difference was found between the median EHI raw scores of the patients and the family members. The median EHI raw scores of the patients were significantly lower than their paired family members. Conclusion: The study failed to prove a leftward shift of handedness in the patients with Schizophrenia and Schizoaffective disorder in the Afrikaner Founder population. Whether or not LRRTM1 is indeed the genetic basis of handedness, remains unclear.

Vroeë afwykende niepsigotiese gedrag in skisofrenie

“…In 'n studie van Afrikanerpasiënte met skisofrenie en SAS, het navorsers gepoog om die hipotese te toets dat hierdie pasiënte meer geneig sou wees om nieregshandig te wees as hulle nieaangetaste familielede en twee aparte kontrolegroepe. Die assosiasie tussen handigheid, geslag en ouderdom van aanvang van siekte in die pasiëntgroepe is ook bepaal (Mataboge et al 2014). Hierdie studie kon nie bewys lewer van 'n linkshandige skuif in Afrikanerpasiënte met skisofrenie en SAS nie.…”

Vatbaarheid vir skisofrenie by 22q11.2-mikroweglatings

“…In 2014 is 'n studie gepubliseer wat die hipotese getoets het dat Afrikanerpasiënte met skisofrenie of SAS meer nieregshandig is (gemengde handigheid of linkshandigheid) as hulle eersterangse familielede en twee kontrolegroepe (Mataboge et al 2014). Die bevindings van dié studie kan beter verstaan word teen die agtergrond van die studie-ontwerp.…”

“…Handigheid van Afrikanerpasiënte met skisofrenie of SAS is vergelyk met dié van hulle nie-aangetaste eersterangse familielede en die twee kontrolegroepe. Die eerste kontrolegroep het bestaan uit mediese studente van Afrikaneroorsprong by die Universiteit van Pretoria (UP), terwyl die tweede kontrolegroep bestaan het uit 500 Afrikanerdeelnemers vanuit die algemene bevolking wat gewerf is by verskeie skole, kerke en tehuise vir bejaardes in Pretoria (Mataboge et al 2014). Die insluiting van twee aparte kontrolegroepe was die gevolg van die onverwagse bevinding van beduidende nieregshandigheid onder die kontrolegroep mediese studente.…”

“…Alhoewel die meeste mense een hand bo 'n ander verkies, is handigheid eerder 'n kwessie van 'n graad van voorkeur as van absolute tipes (Brandler & Paracchini 2014). Die uitkoms van die studie deur Mataboge et al (2014) toon dat Afrikanerpasiënte met skisofrenie en/of SAS as 'n geheel minder nieregshandigheid toon as die studentekontrolegroep. Daar was geen beduidende verskille in handigheid tussen die pasiëntgroep en hulle nie-aangetaste familie of die tweede kontrolegroep as die EHI afsnypunt van ± ~60 gebruik word nie.…”