ATR-16 due to a de novo complex rearrangement of chromosome 16.
We describe a child with ATR-16 [alpha-thalassemia (thal)/mental retardation], who was referred for genetic evaluation because of minor anomalies and developmental delay. Cytogenetic analysis demonstrated a de novo complex rearrangement of chromosome 16. Fluorescence in situ hybridization (FISH) analysis, using chromosome 16 subtelomeric probes, showed that this patient had a deletion of the distal short arm of chromosome 16 that contains the alpha-globin genes and a duplication of 16q. Analysis of the alpha-globin locus by Southern blot showed a half normal dose of the alpha-globin gene. Microsatellite marker studies revealed that the duplicated 16q region was maternal in origin. Hematological studies revealed anemia, hypochromia and occasional cells with Hb H inclusion bodies. A hematological screening for alpha-thal should be considered in patients with mild developmental delay and a suggestive phenotype of ATR-16 with microcytic hypochromic anemia and normal iron status. The stellate pattern of the iris, a new finding in our patient, may contribute to a better clinical delineation of both syndromes, ATR-16 and/or duplication of 16qter.
Gallego
Marta S
MS
Laboratorio de Citogenética, Servicio de Genética, Hospital de Pediatría Professor Dr. Juan P. Garrahan, Buenos Aires, Argentina. mgallego@garrahan.gov.ar
Zelaya
Gabriela
G
Feliu
Aurora S
AS
Rossetti
Liliana
L
Shaffer
Lisa G
LG
Bailey
Kristen A
KA
Bacino
Carlos A
CA
Barreiro
Cristina Z
CZ
D002869:Chromosome Aberrations; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D020732:Cytogenetic Analysis / Q000379:methods; D004252:DNA Mutational Analysis / Q000379:methods; D005838:Genotype; D006447:Hemoglobin H / Q000032:analysis; D006455:Hemoglobins, Abnormal / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D007223:Infant; D008607:Intellectual Disability / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D017354:Point Mutation / Q000235:genetics; D017384:Sequence Deletion; D017085:alpha-Thalassemia / Q000175:diagnosis / Q000235:genetics*
D006455:Hemoglobins, Abnormal; D006447:Hemoglobin H