Three patients with a 45,X/46,X,psu dic(Xp) karyotype

Area of Science:

• Genetics
• Reproductive Biology
• Human Chromosome Studies

Background:

• Isochromosomes for the X chromosome's short arm are rare, typically dicentric with interspersed long arm segments.
• Turner syndrome is associated with various X chromosome abnormalities.

Observation:

• Three unrelated female patients with complete short arm duplication of one X chromosome were identified.
• All patients possessed a 45,X cell line alongside the duplicated X chromosome.
• Clinical presentation included features characteristic of Turner syndrome.

Findings:

• Detailed characterization of the three structurally abnormal X chromosomes was performed using cytogenetic and molecular techniques.
• The parental origin of the duplicated chromosome in two patients was determined.
• The study identified novel cases of complete short arm duplication of the X chromosome.

Implications:

• The findings contribute to the limited case reports of X chromosome short arm isochromosomes.
• Understanding genotype-phenotype correlations is complex due to the co-occurrence of the 45,X cell line.
• Further research may elucidate the role of X chromosome structural abnormalities in Turner syndrome phenotypes.