TY - JOUR
T1 - Monosomy 21q22.11-q22.13 presenting as a Fanconi anemia phenotype
AU - Byrd, Robert S.
AU - Zwerdling, Theodore
AU - Moghaddam, Billur
AU - Pinter, Joseph D.
AU - Steinfeld, Mary Beth
PY - 2011/1
Y1 - 2011/1
N2 - We report on a 5-year-old Caucasian female with multiple anomalies whose deletion, 46,XX,del(21)(q22.11q22.13), was determined by a 105K oligonucleotide-based microarray. This case is a unique deletion that mimicked Fanconi anemia (combination of thrombocytopenia, thumb anomalies, congenital heart defects, borderline small head circumference, strabismus, hydronephrosis, and significant developmental delay) but testing for Fanconi anemia was negative, as was testing for a wide array of genetic/metabolic conditions. Microarray testing done at 5 months failed to demonstrate the interstitial deletion that was found on a newer generation microarray test performed after 3 years of age. When compared to other reported cases of partial monosomy 21q, the unique features of this case include: (1) cleft palate, although high palate is reported in other cases; (2) neonatal thrombocytopenia requiring platelet transfusion; (3) a platelet function defect, reported previously as platelet storage pool defect as part of a familial platelet disorder; and (4) an immune function defect. Similar to other reported patients with terminal 21q deletion, this child had significant developmental delay, and feeding and growth problems. This case also highlights the ability for newer technology microarrays to identify small interstitial deletions previously missed by an earlier version microarray. The advances in the microarray technologies are allowing us to better define new phenotypes and leading to the identification of a diagnosis for many patients who have been previously undiagnosed. Review of the genes involved in these novel deletions allows the caring physician to design surveillance strategies that are custom-designed for these unique patients.
AB - We report on a 5-year-old Caucasian female with multiple anomalies whose deletion, 46,XX,del(21)(q22.11q22.13), was determined by a 105K oligonucleotide-based microarray. This case is a unique deletion that mimicked Fanconi anemia (combination of thrombocytopenia, thumb anomalies, congenital heart defects, borderline small head circumference, strabismus, hydronephrosis, and significant developmental delay) but testing for Fanconi anemia was negative, as was testing for a wide array of genetic/metabolic conditions. Microarray testing done at 5 months failed to demonstrate the interstitial deletion that was found on a newer generation microarray test performed after 3 years of age. When compared to other reported cases of partial monosomy 21q, the unique features of this case include: (1) cleft palate, although high palate is reported in other cases; (2) neonatal thrombocytopenia requiring platelet transfusion; (3) a platelet function defect, reported previously as platelet storage pool defect as part of a familial platelet disorder; and (4) an immune function defect. Similar to other reported patients with terminal 21q deletion, this child had significant developmental delay, and feeding and growth problems. This case also highlights the ability for newer technology microarrays to identify small interstitial deletions previously missed by an earlier version microarray. The advances in the microarray technologies are allowing us to better define new phenotypes and leading to the identification of a diagnosis for many patients who have been previously undiagnosed. Review of the genes involved in these novel deletions allows the caring physician to design surveillance strategies that are custom-designed for these unique patients.
KW - Cleft palate
KW - Microarray
KW - Partial monosomy
KW - Platelet function defect
KW - Severe developmental delay
KW - Thrombocytopenia
KW - Triphalangeal thumbs
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U2 - 10.1002/ajmg.a.33801
DO - 10.1002/ajmg.a.33801
M3 - Article
C2 - 21204218
AN - SCOPUS:78650669921
SN - 1552-4825
VL - 155
SP - 120
EP - 125
JO - American Journal of Medical Genetics, Part A
JF - American Journal of Medical Genetics, Part A
IS - 1
ER -