Direct duplication of chromosome 1, dir dup(1)(p21.2----p32) in a Bedouin boy with multiple congenital anomalies.

Here we describe a Bedouin boy with a de novo duplication of 1p and multiple congenital anomalies. He had microcephaly, convergent squint, anteverted nostrils, malformed ears, micrognathia, hypoplasia of the terminal phalanges, clinodactyly of 5th fingers, simian creases, left inguinal hernia, cryptorchidism, and severe postnatal growth retardation. Our clinical findings are compared with those of previous reports of duplication involving chromosome 1p.

Interstitial deletion of the long arm of chromosome 1 [del(1)(q32q42)].

A severely malformed girl died 7 days after birth and was found to have de novo interstitial deletion of 1q (1q32----1q42). Clinical abnormalities included microcephaly, encephalocele, small eyes with unilateral esotropia, hypertelorism but small prominent nose, highly arched palate, micrognathia, abnormal cry, apparently abnormal low-set ears, short neck with low posterior hair line, narrow shoulders, congenital heart defect, hypoplastic nails, overlap of toes with flat feet, and single umbilical artery.

Ullrich-Turner syndrome in monozygotic twins.

We report on the Ullrich-Turner syndrome in monozygotic twin sisters. The first twin had the syndrome with a 45,X chromosome constitution. The second twin had only minor manifestations of the syndrome with 46,XX/45,X mosaicism. The literature on the Ullrich-Turner syndrome in twins is reviewed.

Segregation of acrocentric chromosome association in familial dicentric Robertsonian translocation t(14p;22p), aneuploidy (trisomy-21) and heteromorphism.

The frequency and types of acrocentric chromosome association were quantitatively analysed in a Down syndrome child with unusual karyotype, 46, XX, -14, -22, t dic (14p;22p), +21, 21S+. Father and 4 sibs were heterozygous carriers for t dic (14p;22p). The variant 21S+ was inherited from the mother. The occurrence of translocation and trisomy in the same individual is extremely rare. Acrocentric chromosome association was analysed in this interesting family to understand the interrelationship of acrocentric chromosome association, Robertsonian translocation and heteromorphism, as possible predisposing factors for nondisjunction. Our findings suggest that acrocentric chromosome association is a heritable and nonrandom phenomenon. Heterozygous carriers for translocations and variants are likely to be at increased risk of nondisjunction. Long term family studies will enable to ascertain the causal-relationship of these factors more precisely.

Sex hormone binding globulin levels in adolescent subjects with diabetes mellitus.

In normal adolescents there is a pubertal fall in circulating levels of sex hormone binding globulin (SHBG) in both sexes which is not explained by classically accepted mechanisms of control of SHBG. Recent in vitro and in vivo evidence has suggested that SHBG is inversely regulated by insulin. In view of this we have compared SHBG levels in 80 adolescent subjects with Type 1 diabetes to those in 61 normal adolescents. In both normals and in Type 1 diabetic subjects there was a pubertal fall in SHBG levels. Contrary to expectations, SHBG levels were not elevated in those with diabetes, but prepubertally were significantly lower in both sexes (boys mean +/- SD, 70 +/- 28 nmol l-1, normals 130 +/- 52 nmol l-1, p less than 0.001; girls, 61 +/- 17 nmol l-1, normals 110 +/- 23 nmol l-1, p = 0.01). In pubertal subjects no differences in SHBG levels were seen between the two groups, or between either sex within any group. In subjects with Type 1 diabetes SHBG levels were unrelated to metabolic control as reflected by HbA1 but were inversely related to pubertal stage (r = 0.55, p less than 0.001). In prepubertal subjects with diabetes, in whom abnormal SHBG levels were found, these levels were weakly related to insulin dose (r = 0.33, p less than 0.05); no such relationship was found in the other groups. The significance of the abnormal SHBG levels in prepubertal children with diabetes and its relationship to any irregularities of their sexual development is unclear.

Unilateral true hermaphrodite with 46,XX/46,XY dispermic chimerism.

A 13 year old female presented with ambiguous external genitalia, right inguinal ovotestis, left ovary, apparently normal Mullerian system, and absent Wolffian system. Cultured lymphocytes showed a 46,XX/46,XY karyotype. Histopathology of the gonads confirmed true hermaphroditism. The presence of two genetically different erythrocyte populations was observed. The findings suggested that the patient is a true hermaphrodite dispermic chimera.

The newly recognised limb/pelvis-hypoplasia/aplasia syndrome: report of a Bedouin patient and review.

A Bedouin infant born to consanguineous parents and grandparents is reported. She had Müllerian aplasia and the phenotypic features of the limb/pelvis-hypoplasia/aplasia syndrome (MIM 276820). Phenotypic variability of this newly recognised syndrome is briefly discussed.

Familial pericentric inversion of chromosome 13, 46,XX,inv (13)(p13;q11): a new variant.

A 10-year-old female with right oblique inguinal hernia was investigated to exclude an XY karyotype. Chromosome analysis of peripheral blood showed 46,XX,inv(13)(p13;q11). In vitro aneuploidy was observed in two cells: a) 46,XX,inv(13), inv(13); b) 47,XX, +inv(13). Her father and three sisters were carriers for inv(13). Herein the authors review briefly familial inv(13)'s and report a new variant involving breakpoints (p13;q11).