Consanguinity and increased risk for schizophrenia in Egypt.
BACKGROUND
Consanguinity has been suggested as a risk factor for psychoses in some Middle Eastern countries, but adequate control data are unavailable. Our recent studies in Egypt have shown elevated parental consanguinity rates among patients with bipolar I disorder (BP1), compared with controls. We have now extended our analyses to schizophrenia (SZ) in the same population.


METHODS
A case-control study was conducted at Mansoura University Hospital, Mansoura, Egypt (SZ, n=75; controls, n=126, and their available parents). The prevalence of consanguinity was estimated from family history data ('self report'), followed by DNA analysis using short tandem repeat polymorphisms (STRPs, n=63) ('DNA-based' rates).


RESULTS
Self-reported consanguinity was significantly elevated among the patients (SZ: 46.6%, controls: 19.8%, OR 3.53, 95% CI 1.88, 6.64; p=0.000058, 1 d.f.). These differences were confirmed using DNA-based estimates for coefficients of inbreeding (inbreeding coefficients as means+/-standard error, cases: 0.058+/-0.007, controls: 0.022+/-0.003).


CONCLUSIONS
Consanguinity rates are significantly elevated among Egyptian SZ patients in the Nile delta region. The associations are similar to those observed with BP1 in our earlier study. If replicated, the substantial risk associated with consanguinity raises public health concerns. They may also pave the way for gene mapping studies.
Mansour
Hader
H
Department of Psychiatry, University of Pittsburgh School of Medicine, Western Psychiatric Institute and Clinic, Pittsburgh, PA 15213, USA.
Fathi
Warda
W
Klei
Lambertus
L
Wood
Joel
J
Chowdari
Kodavali
K
Watson
Annie
A
Eissa
Ahmed
A
Elassy
Mai
M
Ali
Ibtihal
I
Salah
Hala
H
Yassin
Amal
A
Tobar
Salwa
S
El-Boraie
Hala
H
Gaafar
Hanan
H
Ibrahim
Nahed E
NE
Kandil
Kareem
K
El-Bahaei
Wafaa
W
El-Boraie
Osama
O
Alatrouny
Mohamed
M
El-Chennawi
Farha
F
Devlin
Bernie
B
Nimgaonkar
Vishwajit L
VL
D000328:Adult; D016022:Case-Control Studies; D003241:Consanguinity; D004252:DNA Mutational Analysis / Q000379:methods; D004534:Egypt / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D016017:Odds Ratio; D011110:Polymorphism, Genetic / Q000235:genetics*; D012559:Schizophrenia / Q000453:epidemiology* / Q000235:genetics*; D012650:Self Disclosure; D055815:Young Adult