An unusual karyotype in a patient with signs suggestive of Down's syndrome.

Down's syndrome with an unusual karyotype.

Dicentric chromosome in the bone marrow of a child with megakaryoblastic leukaemia and Down's syndrome.

A two year old girl with Down's syndrome (constitutional karyotype: 47 + 21), presenting with pancytopenia, developed acute megakaryoblastic leukaemia (AMKL). Her bone marrow contained an abnormal clone with a novel dicentric chromosome derived from chromosomes 5 and 7 (karyotype 46, XX, -5, -7, +dic (5;7) (p 13; p 11.2), +21. This case provides further evidence for a connection between chromos...

Diagnosis of Down's syndrome in neonates.

The results of karyotyping for Down's syndrome in neonates were surveyed. From local data 36%, and from a national questionnaire, 32% of such samples were negative for Down's syndrome. To examine this, a subset of notes was reviewed for documentation of clinical signs of Down's syndrome. Some characteristics were often recorded, but other common discriminatory characteristics were noted less of...

A case of apparent trisomy 21 without the Down's syndrome phenotype.

We describe a case of apparent trisomy 21 that does not fulfill the criteria for the clinical diagnosis of Down's syndrome (DS). Our patient was subjected to karyotype analysis and found to have full, non-mosaic trisomy 21 in both blood lymphocytes and skin fibroblasts, while examination of the term placenta, which was performed earlier in the course of a different study, had shown mosaicism (7...

Young Child with Down's Syndrome

An infant girl was diagnosed at birth as having Down's syndrome. Cytogenetic studies demonstrated a normal karyotype in the mother and trisomy 21 in the patient (Dr. E. Blank). In February 1963 the patient, aged 9 months, was admitted to the Children's Hospital, Sheffield, with acute laryngo-tracheo-bronchitis. At this time she was noted to have typical features of Down's syndrome (Fig. 1). Her...