Partial Trisomies and Deletions of Chromosome 13

Abstract

With the advent of new banding techniques there have been increasing numbers of patients with trisomies and deletions for specific portions of chromosome 13 discovered. Some authors have suggested a preliminary phenotypic mapping of chromosome 13. We have studied five patients with trisomies and deletion of parts of chromosome 13 using banding techniques and we have attempted a karyotype-phenotype correlation. 1) Deletion 13q31 13qter: karyotype 46,XX,del(13) (13pter 13q31:) is associated with mental retardation, craniofacial asymmetry, microcephaly, wide forehead, short philtrum, large mouth with protruding and wide spaced superior incisors, prominent and wide nasal bridge, large ears, hypertelorism, retinoblastoma of left eye, and kyphoscoliosis. 2) Deletion 13q31/13q32/13q33 13qter: karyotype 46,XY,13r is associated with growth and mental retardation, large eyes, epicanthus, hypertelorism, frontal bossing, high arched palate, short philtrum, protruding and wide spaced superior incisors, simple low set ears, hypoplastic fingernails, posterior prominence of heel, deep crease of hallux, dorsiflexed first toe, and a third toe longer than the other toes in both feet. 3) Trisomy 13q12--13qter: karyotype 46,X,+t(Y;13)(q11:q12)(Ypter Yq11:13q12 13qter:) is associated with trigonocephaly, craniostenosis with prominent metopic suture, epicanthus, colobomata of left iris, high arched palate, dysplastic low set ears, postaxial symmetric polydactyly, abnormal flexion of fingers, hypoplastic fingernails, and bilateral club feet. 4) Trisomy 13q13 13qter: karyotype 46,XX,t(5;13)(p14;q13)(13qter 13q13::5p14 5qter)pat. is associated with growth retardation, microcephaly, craniostenosis, sloping and prominent forehead, protruding nasal bridge, short palpebral fissures, bilateral cleft lip, cleft palate, short neck, abnormal flexion of fingers, simian crease, clinodactyly of fifth fingers, bilateral club feet, and duplication of fifth toe with syndactyly in the right foot. 5) Trisomy 13pter 13q12: karyotype 47,XX,+del(13)(13pter 13q12:) is associated with mental retardation, microophthalmy, enophthalmy, colobomata of iris and glaucoma of left eye, bilateral preauricular dimples, imperforate anus, rectovulvar fistual, and double left calyceal system.