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Microphthalmia (MO-SCWT)

Related Terms:

RBP4

Type: DNA
Sample Types: Cheek brushes/swabs, Fresh EDTA blood, Other
Sample Processing
Cost: $65.00
Species and Breeds:
Canine - Soft-Coated Wheaten Terrier

We do not provide kits. Please collect the sample following the sample collection and shipping instructions before ordering a test.

Clinical Signs:

Abnormally small eyes at birth, with additional eye defects recognized by eye exam, vision impairment.

Life Expectancy:

Not reported, but presumed normal.

Inheritence Mode:

Autosomal recessive with penetrance determined by the maternal genotype (puppies homozygous for disease-associated variant born to a homozygous mother are affected)

Pathology:

Microphthalmos, chorioretinal hypoplasia, and retinal colobomas.

Mutation:

RBP4 and XM_534969.6:c.93_95delGAA

Explanation of Results

GenoType PhenoType Interpretation

1-1 (Homozygous Normal)

Healthy (Normal, Clear)

1-1 (Homozygous Normal) dogs have two copies of the normal allele and NO COPIES of the disease variant allele that is found in dogs affected with Microphthalmia in the breed. 1-1 dogs will not develop signs of Microphthalmia and NONE of their offspring can inherit the disease variant allele from this dog. 1 = Normal allele; 2 = Disease variant allele. Assistance for making breeding decisions for this disease can be found at https://www.vet.upenn.edu/penngen.

1-2 (Heterozygous)

Healthy (Carrier)

1-2 (Heterozygous/Carrier) dogs have one copy of the normal allele and ONE COPY of the disease variant allele that is found in dogs affected with Microphthalmia in the breed. 1-2 dogs will not develop signs of Microphthalmia although each of the offspring has a chance of inheriting the disease variant allele (2). Parents, offspring, breeding partners, and relatives should also be tested. 1 = Normal allele; 2 = Disease variant allele. Assistance for making breeding decisions for this disease can be found at https://www.vet.upenn.edu/penngen.

2-2 (Homozygous Disease Variant)

Dependent on Genotype of Mother (See Interpretation)

2-2 (Homozygous Disease Variant) dogs have both (TWO) copies of the disease variant allele that is found in dogs affected with Microphthalmia in the breed. 2-2 dogs will develop signs of Microphthalmia ONLY if their mother also has the 2-2 genotype. If the mother has the 1-1 or 1-2 genotype, this dog will be normal with respect to Microphthalmia. All of the offspring of this dog will inherit a copy of the disease variant allele from this dog. Parents, offspring, breeding partners, and relatives should also be tested. 1 = Normal allele; 2 = Disease variant allele. Assistance for making breeding decisions for this disease can be found at https://www.vet.upenn.edu/penngen.

References:

Kaukonen M, Woods S, Ahonen S, Lemberg S, Hellman M, Hytönen MK, Permi P, Glaser T, Lohi H. Maternal Inheritance of a Recessive RBP4 Defect in Canine Congenital Eye Disease. Cell Rep. 2018 May 29;23(9):2643-2652. doi: 10.1016/j.celrep.2018.04.118. PMID: 29847795; PMCID: PMC6546432.