Recurrent enlarged nuchal translucency: first trimester presentation of a familial 15q26→qter deletion.

A 15q26 terminal chromosomal microdeletion was associated with markedly enlarged 1st trimester nuchal translucency in three of four pregnancies of a couple seen in our prenatal diagnosis unit. Nuchal translucency was normal in the couple's fourth pregnancy, which did not carry the microdeletion. The diagnosis of a 15q26.2→qter microdeletion was first made when the couple's affected daughter displayed significant postnatal growth delay and minor malformations consistent with this contiguous gene syndrome. The microdeletion was confirmed on archived material from the first pregnancy, and identified prospectively on chorionic villi in the third pregnancy. This is the second reported case of familial recurrence of this microdeletion syndrome. As in the other reported family, no deletion or chromosomal rearrangement was identified in either parent, suggesting gonadal mosaicism as a possible cause. First trimester ultrasound findings in 15q26 terminal deletion syndrome have not previously been described. This family illustrates the utility of performing prenatal chromosomal microarray testing in the presence of ultrasound findings of enlarged nuchal translucency or structural abnormalities.

Reporting of diagnostic cytogenetic results.

This appendix, developed by the staff at the Clinical Cytogenetics Laboratory at the Brigham and Women's Hospital, includes a comprehensive list of current "macros" or standardized statements used to facilitate reporting of cytogenetic results. These are provided as a reference for other laboratories. The statements are organized under the general categories of constitutional or acquired abnormalities and subdivided into analysis type (GTG-banding or FISH). Multi-specimen usage macros are included that can be applied to two or more specimen types.

Potocki-Lupski syndrome: an inherited dup(17)(p11.2p11.2) with hypoplastic left heart.

Low copy repeat (LCR) sequences in 17p11.2 predispose this region to genomic deletions and duplications. Duplication of 17p11.2, also known as Potocki-Lupski syndrome (PTLS), is a well-described microduplication syndrome featuring cognitive and language deficits, developmental delay, autistic behavior, structural cardiovascular anomalies, hypotonia, failure to thrive, apnea, and dysmorphism. We present a mother and her two children who share both dysmorphic features and the dup(17)(p11.2p11.2); the first child was born with hypoplastic left heart (HLH). The dup(17)(p11.2p11.2) was identified by GTG-banding analysis of peripheral blood specimens from all three individuals and confirmed by fluorescence in situ hybridization (FISH) and array comparative genomic hybridization (aCGH). Here we provide a thorough description of the phenotypes of the affected individuals, as well as describe physical features not reported previously for PTLS.

Reporting of diagnostic cytogenetic results.

This appendix, developed by the staff at the Clinical Cytogenetics Laboratory at the Brigham and Women's Hospital, includes a comprehensive list of current "macros" or standardized statements used to facilitate reporting of cytogenetic results. These are provided as a reference for other laboratories. The statements are organized under the general categories of constitutional or acquired abnormalities and subdivided into analysis type (GTG-banding or FISH). Multi-specimen usage macros are included that can be applied to two or more specimen types.

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. We report a case of a 39-year-old primigravida with unremarkable pregnancy, who had amniocentesis due to advanced maternal age. Chromosomal analysis demonstrated a long arm (q) variant of chromosome 9 with an enlarged heteromorphic area, approximately three times longer than known reported variants. Prenatal analysis demonstated an identical variant in the probands phenotypically normal father, uncle, and paternal grandmother, confirming an apparently "normal" variant.

Reporting of diagnostic cytogenetic results.

This appendix, developed by the staff at the Clinical Cytogenetics Laboratory at the Brigham and Women's Hospital, provides a comprehensive list of the facilities' current "macros" or standardized statements, used to facilitate reporting of cytogenetic results. These are provided as a reference for other laboratories. The statements are organized under the general categories of constitutional or acquired abnormalities and subdivided into analysis type (GTG-banding or FISH). Multi-specimen usage macros are included that can be applied to two or more specimen types.