The Role of Genetic Counseling in Prevention of Primary Congenital Glaucoma

Primary congenital glaucoma (PCG) (OMIM: 231300) is an inherited ocular illness, which leads to permanent blindness. Up to now, three dissimilar loci are mapped for PCG. The most common locus detected for this disease is cytochrome P450 (CYP1B1; GLC3A) mutations. Expression and penetrance of PCG varies from 40% to 100%. It seems the high incidence in the oriental communities is due to consanguineous matrimonies. PCG happens in both sporadic and familial patterns. Inheritance in familial cases is usually autosomal recessive, which sometimes manifested as incomplete penetrance. Pseudo - dominant transmission was also reported.
The paper reports a case of genetic counseling in Iran that the client couple had family marriage and demanded pre-pregnancy consultation, but the male was healthful and unaware of treated genetic disorder in his infancy. After history taking, the first candidate gene (CYP1B1) in the husband and his parents were amplified by polymerase chain reaction (PCR), sequenced using Sanger technique; therefore, the control subjects and patients were analyzed to identify PCG mutations.
The husband and his mother were compound heterozygote for CYP1B1 gene mutations including two variations in 61 and 368 codons. Also his father was heterozygote for one variant. More investigations showed that the wife (husband’s cousin) did not mention mutations. The local certified counselor/physician provided genetic counseling, should investigate surgery reason and its description for individuals with therapeutic or plastic surgery history. This early and reliable diagnosis of the disease is vital for the next generation, especially in family marriage cases, prenatal diagnosis is provided, also, appropriate and early medical and surgical prognoses can be performed. This causes prevention of visual loss and save vision of the child.