45,X/46,XX mosaicism in a mother and one of her discordant monozygotic twin daughters: report of one case.

Decreased fertility is one of the characteristics of Turner syndrome. Ovarian function in women with Turner syndrome is believed to be impaired because of an abnormal and very rapid maturation of oocytes and follicles. About 30% of mosaic Turner patients have partial ovarian function during puberty, but only 2-5% of them will ever become pregnant. We describe a woman with a mosaic form of Turner syndrome (45,X [6]/146,XX [94] karyotype from blood lymphocytes), who had a spontaneous puberty and normal fertility. After her second pregnancy, she gave birth to a set of monozygotic female twins; Twin B presented with a mild Turner syndrome phenotype and Twin A with a normal female phenotype. Karyotypic analysis performed on amniotic fluid and fetal blood samples demonstrated a normal 46,XX chromosome constitution in Twin A and a 45,X/46,XX mosaicism (27%:73% for amniotic fluid and 6%:94% for fetal blood) in Twin B. Postnatal cytogenetic investigation of blood lymphocytes showed the 45,X [7]/46,XX [93] mosaicism in Twin B. Further investigations of blood lymphocytes in both girls at the age of 4 years showed Twin A with a 46,XX karyotype and Twin B with a 45,X [4]/46,XX [96] mosaicism. The phenotype of twin A had a normal appearance, but webbing of the neck, low posterior hair line, shield chest, and mild psychomotor retardation were evident in Twin B.

Anterior mediastinal immature teratoma with precocious puberty in a child with Klinefelter syndrome.

Klinefelter syndrome occurs in approximately 1 in 1000 males. A 4-year-old boy presented with precocious puberty and an anterior mediastinal mass. Serum alpha-fetoprotein and human chorionic gonadotropin levels were mildly increased. Computed tomography revealed a germ cell tumor (GCT) of the mediastinum. Complete resection of the tumor was performed. Histologic analysis revealed an immature teratoma. Males with Klinefelter syndrome develop GCTs at a rate 50 times higher than unaffected males. This case report calls attention to the need to rule out Klinefelter syndrome in boys who present with precocious puberty and a mediastinal GCT.

Six cases of deletion 9p24 and trisomy 19q13.4 inherited from a familial balanced translocation.

The deletion 9p with trisomy 19q syndrome is a rare disorder. We report 2 adults and 4 children with deletion 9p and trisomy 19q due to familial balanced 9p;19q translocation with clinical features suggestive of monosomy 9p. The children had dysmorphic features and psychomotor retardation while the adults were self-sufficient but worked in a sheltered environment. High-resolution chromosome analysis and fluorescence in situ hybridization confirmed that the 6 cases of unbalanced translocation, der(9)t(9;19)(p24.1;q13.4) were inherited from a balanced translocation carrier, t(9;19)(p24.1;q13.4). The dysmorphic features included trigonocephaly, small nose with stunted tip, and long philtrum. Associated anomalies included wide-set nipples, extra finger flexion creases, hernia, external genitalia hypoplasia, scoliosis, and hypopigmented skin patch. We suggest that genetic counseling is necessary for those who have family members with dysmorphic features and/or major anomalies and/or psychomotor retardation.

Partial duplication of 3q and distal deletion of 10q inherited from a maternal balanced translocation.

Partial trisomy 3q syndrome is often the result of an unbalanced translocation or inversion. The duplicated segments are mostly from 3q25 to 3qter. We describe a karyotype of 46,XY,der(10)t(3;10)(q25.3;q26.1) in a 1-day-old male infant who presented with multiple congenital anomalies including synophrys, a long philtrum, thin lips with down-turned angles of the mouth, micrognathia, a high-arched and cleft palate, clenched hands, genital hypoplasia, cryptorchidism, a large ventricular septal defect, a subependymal cyst, and corpus callosum hypoplasia. The patient had cardiopulmonary distress resulting from multiple congenital anomalies. He died of heart failure at the age of 18 days. The chromosome aberration resulted from a maternal balanced translocation. The dup(3q) syndrome superficially resembles but can be distinguished from Brachmann-de Lange syndrome. Craniofacial features, cleft palate and urinary tract anomaly are more frequent in dup(3q) syndrome. Oligodactyly and phocomelia are more characteristic of Brachmann-de Lange syndrome.

Interstitial deletion of chromosome 14q in a Taiwanese infant with microcephaly.

Deletion (14)(q11.2q13.1) is a rare cytogenetic abnormality associated with severe neurological deficit, microcephaly and psychomotor retardation. We report a case of de novo interstitial deletion of chromosome (14)(q11.2q13.1) in an 8-month-old girl, who presented with marked microcephaly, a nearly closed anterior fontanelle, dysmorphic facies, severe neurological deficits, and delayed developmental milestones. Three-dimensional computed tomography of the brain showed premature closure of the coronal suture and magnetic resonance imaging of the brain showed frontal atrophy and hypoplastic corpus callosum.

De novo 4p-syndrome with oligohydramnios sequence.

4p-syndrome, or Wolf-Hirschhorn syndrome, is associated with a deletion of chromosome 4p16.3 and involves multiple malformations that result in delayed growth and development and also facial dysmorphism. We report a case of Wolf-Hirschhorn syndrome in a female infant with a 4p deletion, for which the breakpoint was detected at p14. This patient had bilateral renal hypoplasia resulting from the oligohydramnios sequence (Potter syndrome), including characteristic facial abnormalities, deformed limbs, and pulmonary hypoplasia. Patent ductus arteriosus, ascites, and bilateral renal hypoplasia were noted. The patient had frequent pulmonary infections and died when she was 39 days old.

De novo chromosome translocation t (2; 11) (p25.1; p13) in a patient with aniridia and genitourinary abnormalities.

Aniridia is a rare condition occurring in 1 in 64,000 to 1 in 96,000 live births. Approximately one third of cases are sporadic and carry a 30% risk of Wilms' tumor developing before the age of 5. The remaining 66% are inherited in an autosomal dominant fashion. The aniridia candidate gene (PAX6) has a key role as a master regulator in the development of eye and central nervous tissues. The Wilms' tumor predisposing gene (WT1) plays an important role in the development of genitourinary tract diseases such as hypospadias, cryptorchism, horse-shoe kidney, and Wilms' tumor. The WT1 and PAX6 genes are about 700 kb apart, with the WT1 gene located centromeric to PAX6 in chromosome 11p13. We report a patient with incomplete aniridia, ptosis, hypospadias, and cryptorchism. Cytogenetic analysis revealed the presence of a de novo reciprocal translocation 46, XY, t (2; 11) (p25.1; p13) without microscopic deletion. We suggest that haploinsufficiency in PAX6 and WT1 genes resulted in aniridia and associated genitourinary abnormalities.

Multiple congenital anomalies in association with supernumerary chromosome 47 inherited from a maternal balanced translocation.

Tertiary trisomy is uncommon and may arise only when one of the derivatives is small and, in the abnormal individual with karyotype 47, exists as a supernumerary derivative chromosome (+der). We describe a case of 47, XY, +der(9)t(5;9) (q33.1;q13)mat. The patient (a 1-day-old male) presented with multiple congenital anomalies including microcephaly, wide fontanelles and sutures, microphthalmia, deep-set eyes, short palpebral fissures, bulbous nose, wide nasal bridge, high arched palate, low-set and posteriorly rotated ears, micrognathia, short neck, ptosis, patient ductus arteriosus, hypoplastic external genitalia, cryptorchidism, inguinal hernia, flexion contractures of joints, short stature, clenched hands, rocker-bottom feet, simian crease, distal mottling of the skin, nail hypoplasia, hypoplasia of bones and hydrocephalus. The supernumerary derivative chromosome resulted from a meiotic recombination of a maternal balanced translocation, t(5;9) (q33.1;q13), suggesting that 3:1 disjunction in the oocyte occurred.