ABSTRACT
A two-year-old girl with a "pure" 21pter leads to q21 monosomy secondary to a 3:1 segregation of a maternal translocation t(14;21)(p12;q22) is described. The father's karyotype was 46,XY,t(5;18)(q32;q22). This observation permits to further delineate the 21q proximal monosomy syndrome and to comment the very rare finding of a couple in which both partners have different reciprocal translocations.
Subject(s)
Abnormalities, Multiple/genetics , Aneuploidy , Chromosome Aberrations/genetics , Chromosomes, Human, 13-15/ultrastructure , Chromosomes, Human, 16-18/ultrastructure , Chromosomes, Human, 21-22 and Y/ultrastructure , Chromosomes, Human, 4-5/ultrastructure , Translocation, Genetic , Abnormalities, Multiple/pathology , Adult , Chromosome Aberrations/pathology , Chromosome Disorders , Female , Humans , Infant , Karyotyping , Male , SyndromeABSTRACT
A two-year-old girl trisomic for the segment 1q25 leads to qter and partially monosomic for band 18q23 as a consequence of a de novo t(1;18)(q25;q23) is reported. Most of the proposita's clinical findings have been described in the 1qter trisomy and some others in the 18q monosomy. This observation is interpreted as additional evidence of epi-, iso-, and hypostatic interactions at the chromosomal level.
Subject(s)
Aneuploidy , Chromosomes, Human, 1-3/ultrastructure , Chromosomes, Human, 16-18/ultrastructure , Trisomy , Abnormalities, Multiple/genetics , Child, Preschool , Female , Humans , Intellectual Disability/genetics , KaryotypingSubject(s)
Chromosome Fragility , Intellectual Disability/genetics , Sex Chromosome Aberrations/genetics , Sex Chromosomes , Testis/pathology , X Chromosome , Adolescent , Adult , Female , Humans , Hyperplasia , Male , SyndromeABSTRACT
A 10-day-old girl affected with 22q12 leads to qter "pure" trisomy as a consequence of recombination within a maternal pericentric inversion (22)(p13q12) is described. A phenotypical comparative analysis reveals that the proposita's phenotype is strikingly similar to that of the trisomy 22 syndrome. Arylsulphatase-A activity was above normal levels and interpreted to be the result of a triple dosage of the gene, whose localization would be within the 22q12 leads to qter segment. It is concluded that the segment 22q12 leads to qter, rather than band q11 as previously suggested, plays an important role in determining the phenotypical abnormalities which characterize the trisomy 22 syndrome.
Subject(s)
Chromosomes, Human, 21-22 and Y , Trisomy , Abnormalities, Multiple/genetics , Chromosome Inversion , Female , Humans , Infant, Newborn , Phenotype , Recombination, GeneticABSTRACT
A 3-month-old boy with a 46,XY,--21,+t(21;21)(pter leads to q22.3::q22.3 leads to q11::p11 leads to pter) karyotype, implicating trisomy for the 21q11 leads to 21q22.2 segment and monosomy for the 21q22.3 sub-band, is described. Most of the clinical features corresponded to Down syndrome ; other signs such as large ears, prominent nasal bridge and retromicrognathia were interpreted as the expression of 21q22.3 monosomy. The abnormal monocentric chromosome had satellites and stalks on both ends as a result of a 21q;21q translocation followed by deletion of one centromere region. Despite similar stalk size and NOR-Ag positiveness a significantly higher association frequency of the centrometric end as compared to the acentric end was found. This observation suggests that the satellite association phenomenon is not exclusively NOR-dependent, but that the centromeric and/or p11 regions of acrocentrics also play an important role.
Subject(s)
Chromosome Deletion , Chromosomes, Human, 21-22 and Y , Down Syndrome/genetics , Translocation, Genetic , Centromere , Humans , Infant , Male , Nucleolus Organizer RegionABSTRACT
A girl of 9-10/12 years of age with 46,XX,r(13)(p11q34) karyotypes was studied. She presented some clinical and radiological features, such as pectus excavatum, scalp alopecic area, 12th rib agenesis, hypoplastic pelvis, small gluteal pits and hypoplasia of the external genitalia in a female, which have never been previously described in other cases with ring 13 chromosomes. Cytogenetically, in vivo and in vitro viability of complete monosomic and partially trisomic and tetrasomic cells was found. The presence of nucleolus organizer regions and association of the ring 13 with other acrocentrics question the exclusivity of these attributes to acrocentrics p12.
Subject(s)
Abnormalities, Multiple/genetics , Chromosome Aberrations/genetics , Chromosomes, Human, 13-15 , Child , Chromosome Banding , Chromosome Disorders , Female , Humans , Intellectual Disability/genetics , Karyotyping , Microcephaly/genetics , Mosaicism , Toes/abnormalitiesABSTRACT
A 5 10/12 year-old boy with a 47,XYY karyotype, micropenis, scrotal hypospadias and right testicular regression is described. Normal for age basal plasma testosterone levels which increased after hCG stimulation were interpreted as an adequate response of the left testicular Leydig cells. The review of similar cases did not permit definite conclusions concerning the relationship between the abnormal genitalia and the XYY karyotype.
Subject(s)
Genitalia, Male/abnormalities , Sex Chromosome Aberrations/genetics , Aneuploidy , Child, Preschool , Humans , Hypospadias/genetics , Karyotyping , Male , Penis/abnormalities , Scrotum/abnormalities , Testis/abnormalities , Y ChromosomeABSTRACT
An infant with a partial trisomy 18(pter yields q11:) is described. The patient's phenotype consists of many features of complete trisomy 18. The findings are compared with those from similar cases reported in the literature permitting to conclude that 18q121-q122 segment is the "critical" zone which when trisomic, causes the severe stigmata (inner organ malformations and early death) of the complete trisomy 18.
