Ring chromosome 18: a case report.

Area of Science:

• Genetics
• Clinical Genetics
• Cytogenetics

Background:

• Ring chromosomes are rare chromosomal abnormalities resulting from deletions and fusion at both chromosome ends.
• Ring 18 syndrome, a specific type, is associated with severe intellectual disability, microcephaly, and congenital malformations.

Observation:

• A 2.5-year-old male patient presented with cleft lip, club foot, intellectual disability, and cryptorchidism.
• G-banding chromosomal analysis revealed the karyotype 46, XY, r(18) (p11.32 q21.32).

Findings:

• The patient's clinical presentation aligns with the known features of ring 18 syndrome.
• The specific breakpoints on chromosome 18 (p11.32 and q21.32) were identified.

Implications:

• This case highlights the importance of cytogenetic investigation in patients with unexplained developmental and physical abnormalities.
• Accurate diagnosis of ring 18 syndrome facilitates appropriate clinical management and genetic counseling.