M.R. Verschraegen-Spae

Mosaic tetrasomy 15q25→qter in a newborn infant with multiple anomalies

We describe a premature boy with metopic craniosynostosis, facial anomalies, atrial-septal defect, hydronephrosis and flexion contractures of lower limbs, and mosaic tetrasomy 15q25-->qter. The extra chromosome material was present in the form of an acentric marker. A number of clinical manifestations observed in this child were also found in 3 previously reported patients who were trisomic for the same part of chromosome 15 and in 2 patients who were tetrasomic for a larger segment of 15q.

Familial pericentric inversion of chromosome 18: behavioral abnormalities in patients heterozygous for either the dup(18p)/del(18q) or dup(18q)/del(18p) recombinant chromosome

We describe a family in which the largest hitherto reported pericentric inversion of chromosome 18, inv(18)(p11.22q23), segregates. Individuals heterozygous for the nonrecombinant inversion were unaffected. However, those heterozygous for either the dup(18p)/del(18q) or dup(18q) /del(18p) recombinant exhibited mild learning difficulty, personality disorders and deficient social behavior in the absence of mental retardation. Of the three family members tested, the behavioral abnormalities were more prominent in the two individuals with the dup(18p)/del(18q) recombinant than in the one with the dup(18q)/del(18p) recombinant. Genetic counseling issues for this family, in particular for the affected, include the enhanced probability of reduced fertility as well as the recurrence risk of the parental inversion equaling 1/2 in surviving offspring. This observation kindles the interest in determining the frequency of subtelomeric rearrangements in individuals with learning difficulty and deficiency in social interaction, phenotypic features often considered to be of multifactorial causation.

Trisomy 3 mosaicism in a patient with Bartter syndrome.

The diagnosis of Bartter syndrome was established in a 21 year old female patient, who presented with hypokalaemia and hyperkaluria, alkalosis, hyperreninism, hyperaldosteronism, and decreased fractional chloride reabsorption in the ascending limb of Henles loop. Her stature was very short (140 cm) with otherwise normal body proportions. At birth, a coloboma of the right eye, dislocation of the left hip, and syndactyly of the second and third toes of the right foot were present. Since the age of 13, -she has suffered from recurrent attacks of gouty arthritis. At the age of 20, she presented with hyperglycaemia and glucosuria for which she had received insulin for one year. Family investigations revealed consanguinity between the parents (F=1/256). Karyotyping was first performed at the age of two, and showed trisomy 3 in 10% of leucocytes. At the age of 21, another cytogenetic evaluation was performed which revealed mosaicism for a normal and a trisomic cell line. In cultured blood leucocytes,

Familial meningioma: Case report with cytogenetic study

A family is presented of which two members were shown to have an intracranial meningioma. We performed a chromosome study in the affected living individual and several other relatives, with special attention for chromosome 22 anomalies. In neither of them a chromosomal abnormality could be detected. However, in view of the recent cytogenetic findings reported in meningioma, it is suggested that karyotyping should be performed in every family with two or more members affected by meningioma.