Prenatal diagnosis of mosaic complete trisomy 1q

A prenatally recognizable malformation syndrome associated with a recurrent post‐zygotic chromosome rearrangement der(Y)t(Y;1)(q12:q21)

“…Trisomy 1q21 or larger, such as 1q11 and 1q12 is incompatible with life, with virtually all cases either stillborn or dead within minutes to days after birth [Schmitt et al, 2009]. The longest postnatal survival reported was 5 months [Patel et al, 2009].…”

Mosaic trisomy 1q: a recurring chromosome anomaly that is a diagnostic challenge and is associated with a Fryns-like phenotype

“…Trisomy 1q of the entire long arm is a rare diagnosis, and to our knowledge, only 12 cases have been previously reported . Our report describes six additional cases, all of whom had mos 46,X,der(Y)t(Y;1)(q12;q12)/46,XY or mos 46,X,der(Y)t(Y;1)(q12;q21)/46,XY.…”

“…Trisomy of the entire long arm of chromosome 1 as the sole imbalance is an exceedingly rare chromosomal abnormality, with 12 cases reported in the literature . The majority of cases result from an unbalanced translocation between chromosome 1 and either chromosome Y or an acrocentric chromosome.…”

“…Four cases have involved translocations with the short arm of an acrocentric chromosome, including chromosomes 14, 15 and 22, with no clinical consequence of loss of that short arm . There has also been a report of a case of mosaic trisomy for the entire long arm of chromosome 1 caused by a free‐standing duplicated copy of the entire long arm of chromosome 1, 47, XY, +del(1)(p11) …”

“…All of the ten prenatally diagnosed cases had multiple congenital anomalies, including elevated first‐trimester nuchal translucency, congenital diaphragmatic hernia, omphalocele, brain anomalies and cystic kidneys . Other common prenatal or post‐natal features included microphthalmia; anomalies of the brain such as ventriculomegaly, agenesis of the corpus callosum and cerebellar vermis hypoplasia; and hand abnormalities including camptodactyly, syndactyly, abnormally placed digits and hypoplastic nails.…”