Interstitial microduplication of Xp22.31: Causative of intellectual disability or benign copy number variant?

The use of comparative genomic hybridization (CGH) and single nucleotide polymorphism (SNP) arrays has dramatically altered the approach to identification of genetic alterations that can explain intellectual disability and /or congenital anomalies. However, the discovery of numerous copy number changes with benign or unknown clinical significance has made interpretation problematic. Submicroscopic duplication of Xp22.

Extreme variant of enlarged heterochromatin region on chromosome 9Q in a normal child and multiple family members.

Heteromorphisms of chromosome 9 are among the most common variations in the human karyotype. The pericentromeric polymorphisms of chromosome 9 include variations in the size of q-arm heterochromatin, pericentric inversions, and rarely, additional C-band-negative, G-band-positive material. The finding of a polymorphic variant, either in prenatal screening or in chromosomal analysis for phenotypic abnormalities, may cause parental anxiety and initiate genetic counselling.

A case study of "disorganized development" and its possible relevance to genetic determinants of aging.

In 1932, Bidder postulated that senescence results from "continued action of a (genetic) regulator (of development) after growth ceases (maturation occurs)." A 16-year-old girl who physically appears to be an infant has not been diagnosed with any known genetic syndrome or chromosomal abnormality. The subject's anthropometric measurements are that of an 11-month-old.

A patient with an interstitial duplication of chromosome 5p11-p13.3 further confirming a critical region for 5p duplication syndrome.

Partial or complete trisomy 5p has been associated with characteristic facial features, developmental delay, seizures, congenital heart defects, and respiratory compromise. We present a child with developmental delay, seizures, and congenital cardiac anomalies found to have a previously unreported de novo interstitial duplication of chromosome 5p, 46,XX,dup(5) (p11p13.3).

Specific extra chromosomes occur in a modal number dependent pattern in pediatric acute lymphoblastic leukemia.

Children with acute lymphoblastic leukemia (ALL) and high hyperdiploidy (>50 chromosomes) are considered to have a relatively good prognosis. The specific extra chromosomes are not random; extra copies of some chromosomes occur more frequently than those of others. We examined the extra chromosomes present in high hyperdiploid ALL to determine if there were a relation of the specific extra chromosomes and modal number (MN) and if the extra chromosomes present could differentiate high hyperdiploid from near-triploid and near-tetraploid cases.

Composite adrenal anaplastic neuroblastoma and virilizing adrenocortical tumor with germline TP53 R248W mutation.

Composite tumors are extremely rare. Such tumors in adrenal glands are usually of neuroendocrine-neural type and occur mostly in adults. Their pathogenesis remains elusive.

Chromosome 3p25 deletion in mother and daughter with minimal phenotypic effect.

3p25 deletion syndrome is characterized by mental retardation, growth retardation, hypotonia, microcephaly, ptosis, and micrognathia. Of the 42 persons with this deletion syndrome cited in the literature, only 2 patients, a mother-daughter pair, have previously been reported without apparent clinical consequence. We present a second mother-daughter dyad with a terminal 3p25.

Translocation breakpoint in two unrelated Tourette syndrome cases, within a region previously linked to the disorder.

Tourette syndrome (TS) is a complex neuropsychiatric disorder characterized by both motor and vocal tics. The etiology of TS is poorly understood; however, evidence of genetic transmission arises from family and twin studies. A complex mode of inheritance has been suggested, likely involving contributions of several genes with different effect size.

Hepatosplenic gamma/delta T-cell lymphoma with isochromosome 7q, translocation t(7;21), and tetrasomy 8 in a 9-year-old girl.

The authors report a child younger than age 15 years with a rare hepatosplenic gamma/delta T-cell lymphoma, which is highly aggressive and primarily seen in young men. A 9-year-old girl presented with thrombocytopenia and hepatosplenomegaly. Bone marrow analysis revealed a metastatic pleomorphic lymphoma of peripheral T-cell phenotype, with rearrangement of the T-cell receptor gamma/delta and expression of CD3 and CD16/56.