Segregating reciprocal (4;21) (q21;q21) translocation with proposita trisomic for parts of 4q and 21.

The segregation of a balanced reciprocal (4;21)(q21;q21) translocation is described. The family was ascertained through a clinically abnormal proposita with an unbalanced karyotype 47,XX,+der(21),t(4;21)(q21;q21)mat. The proposita was trisomic for regions 4q2, 4q3, 21p, and 21q1. Symptoms that might be attributed to the partial trisomy for parts of 4q were narrow bird face with slanting forehead, prominent nasal bridge and small mandible, downward pointing corners of the mouth, deformed ears, palpebral ptosis, and bushy eyebrows. Similar symptoms occur in other trisomy and deletion syndromes.