Quantifying Environmental Risk Factors for Multiple Sclerosis in Discordant Monozygotic Twins: A Case Report.

Relative contribution of genetic and environmental risk factors in complex disorders is widely explored through discordant identical twins. Multiple sclerosis is a demyelinating disease of the central nervous system in which the interplay of genetic and environmental risk factors define the disease pathogenicity. Robust epidemiological studies in different populations suggested that active levels of serum vitamin D and viral load implicate in MS pathogenicity and severity. In order to refine non-shared components of susceptibility factors in MS, we investigated the role of serum 25-hydroxyvitamin D and viral infection in a pair of identical twins remained discordant for MS during the course of 5 years follow up. Here we report serological finding regarding the viral load and serum 25-hydroxyvitamin D level in a pair of discordant monozygotic twins. Based on our observation, lower levels of serum 25-hydroxyvitamin D and higher anti-viral IgG titre was consistent with the disease statues in the affected sib.

Two Cases of Mirror-Image Eye Anomalies in Monozygotic Twins

We report two cases of mirror image anomalies in two different pairs of monozygotic twins. In case 1, the twins exhibited mirroring of strabismus and refractive errors. Twin 1 had 35 prism diopters (PD) right intermittent exotropia at distant fixation and myopic anisometropia that was spherical 2.00 diopters more myopic in the right eye. Twin 2 had 35 PD left intermittent exotropia at distant fixation and her left eye was more myopic by - spherical 1.00 diopters. In case 2, the twins were diagnosed with infantile nystagmus with upbeat jerk. Twin 1 exhibited a habitual head turn of 30degrees to the left with dampening of her nystagmus in dextroversion. Twin 2 also exhibited abnormal head position, but in his case the habitual turn was 30degrees to the right. We believe that this is the first report describing mirror imaged intermittent exotropia with anisometropia and infantile nystagmus with opposite abnormal head positions in pairs of monozygotic twins.

Disorder of Sex Development with 5alpha-reductase Deficiency in Identical Twins / 대한소아내분비학회지

Children with abnormal sex development may present with ambiguous genitalia in the newborn period or lacking of secondary sexual characteristics in puberty. Clinicians should make a prompt and accurate diagnosis and counsel parents on therapeutic options to minimize or avoid medical and psychological complications. 5alpha-reductase deficiency is a rare autosomal recessive disorder of sex development caused by a mutation of the 5alpha-reductase type 2 gene. As a result, there is an abnormality in conversion of testosterone (T) to dihydrotestosterone (DHT) and children with 5alpha-reductase deficiency are born with ambiguous genitalia. Here, we report identical twins who presented with ambiguous genitalia with a 46,XY karyotype and were diagnosed as 5alpha-reductase deficiency.

Simultaneous Occurrence of Bilateral Legg-Calve-Perthes Disease in Identical Twins / 대한정형외과학회잡지

This report describes simultaneous bilateral Legg-Calve-Perthes disease (LCPD) development in four-year-old identical male twins. Moreover, the twins showed head involvement patterns with mirror symmetry. We included a review of the literature on this rare condition and discussed the genetic risks associated with LCPD.

Kaposi's Varicelliform Eruption in a Pair of Identical Twins / 대한피부과학회지

Kaposi's varricelliform eruption is a characteristic syndrome of disseminated vesiculopustules superimposed on variable pre-existing dermatoses. Among these, atopic dermatitis is most common disease. We report two cases of Kaposi's varicelliform eruption associated with atopic dermatitis in a pair of identical twins. Diagnosis was made by the history, clinical feature, histologic examination and serologic test. These patients' condition was much improved by the treatment with antiviral agent and antibiotics.

Minimal Change Disease and Focal Segmental Glomerulosclerosis in Identical Twin Brothers / 대한신장학회잡지

The simultaneous occurrence of primary glomerulonephritis in identical twins has been rarely reported previously. It has suggested that genetic factors may play an important role in the pathogenesis of primary glomerulonephritis. We describe a pair of 17-year-old identical twin brothers with asymptomatic proteinuria, one with histologically proven minimal change disease and the other with focal segmental glomerulosclerosis. HLA typing in twin brothers revealed an identical phenotype consisting of A25, A33, B44, B54, Cwl, Cw7, DR7 and DRB1. To our knowledge, this is the first case of glomerulonephritis in identical twins in Korea.