Segregation Analysis

Author(s):  
R. C. Elston
Keyword(s):  
1995 ◽  
Vol 15 (9) ◽  
pp. 1307-1313 ◽  
Author(s):  
J. Coresh ◽  
T.H. Beaty ◽  
V.L. Prenger ◽  
J. Xu ◽  
P.O. Kwiterovich

2021 ◽  
Vol 22 (15) ◽  
pp. 7842
Author(s):  
Susanne Kohl ◽  
Britta Baumann ◽  
Francesca Dassie ◽  
Anja K. Mayer ◽  
Maria Solaki ◽  
...  

Achromatopsia (ACHM) is a rare autosomal recessively inherited retinal disease characterized by congenital photophobia, nystagmus, low visual acuity, and absence of color vision. ACHM is genetically heterogeneous and can be caused by biallelic mutations in the genes CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, or ATF6. We undertook molecular genetic analysis in a single female patient with a clinical diagnosis of ACHM and identified the homozygous variant c.778G>C;p.(D260H) in the CNGA3 gene. While segregation analysis in the father, as expected, identified the CNGA3 variant in a heterozygous state, it could not be displayed in the mother. Microsatellite marker analysis provided evidence that the homozygosity of the CNGA3 variant is due to partial or complete paternal uniparental isodisomy (UPD) of chromosome 2 in the patient. Apart from the ACHM phenotype, the patient was clinically unsuspicious and healthy. This is one of few examples proving UPD as the underlying mechanism for the clinical manifestation of a recessive mutation in a patient with inherited retinal disease. It also highlights the importance of segregation analysis in both parents of a given patient or especially in cases of homozygous recessive mutations, as UPD has significant implications for genetic counseling with a very low recurrence risk assessment in such families.


2012 ◽  
Vol 40 (01) ◽  
pp. 26-34 ◽  
Author(s):  
T. Bilzer ◽  
S. Petri ◽  
G. Schanen ◽  
M. Fehr ◽  
O. Distl ◽  
...  

Summary Objective: To prove the hypothesis that a polyneuropathy in Alaskan Malamutes has a genetic background. Material and methods: Pedigrees of 131 related Alaskan Malamutes were included in the current study. Neurological examination, electrodiagnosis as well as muscle and nerve biopsies could be performed in 10 dogs. Information about the disease status of the other 121 Alaskan Malamutes were supplied by referring veterinarians, breeders and owners. Segregation analysis using four different models (monogenic, polygenic, mixed monogenicpolygenic and the phenotypic model) was performed on 71 dogs to test the different mechanisms of genetic transmission. Results: In seven clinically affected dogs abnormal electromyographic findings and reduced nerve conduction velocity were detected. Suspected diagnosis of polyneuropathy was confirmed by nerve biopsy results, characterized by axonal degeneration and hypomyelination. Muscle specimens revealed signs of neurogenic myopathy. Three related clinically normal Alaskan Malamutes also displayed moderate neuromuscular changes in histopathology. In the segregation analysis the polygenic model proved as best suitable to explain the observed segregation pattern among all other models tested. Conclusion: The current study could demonstrate that polyneuropathy in Alaskan Malamutes is a hereditary disease with variable phenotypic expression ranging from severely affected to subclinical forms, which has to be considered in future gene analysis studies.


1998 ◽  
Vol 41 (6) ◽  
pp. 1064-1071 ◽  
Author(s):  
David T. Felson ◽  
Nat N. Couropmitree ◽  
Christine E. Chaisson ◽  
Marian T. Hannan ◽  
Yuqing Zhang ◽  
...  

1980 ◽  
Vol 30 (6) ◽  
pp. 350-356 ◽  
Author(s):  
C.L. Carter ◽  
C.S. Chung

1987 ◽  
Vol 4 (6) ◽  
pp. 425-432 ◽  
Author(s):  
Masao Kanamori ◽  
Newton E. Morton ◽  
Keiko Fujiki ◽  
Kiyotaro Kondo ◽  
D. C. Rao ◽  
...  

1993 ◽  
Vol 43 (3) ◽  
pp. 141-146 ◽  
Author(s):  
D.I.W Phillips ◽  
D.C. Shields ◽  
J.M. Dugoujon ◽  
L. Prentice ◽  
P. McGuffin ◽  
...  

BMC Cancer ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Leila Mohammadi ◽  
Maaike P Vreeswijk ◽  
Rogier Oldenburg ◽  
Ans van den Ouweland ◽  
Jan C Oosterwijk ◽  
...  

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