Townes syndrome. A distinct multiple malformation syndrome resembling VACTERL association

Kidney failure in Townes-Brocks syndrome: an under recognized phenomenon?

Though uncommon, kidney malformations are described in several cases of Townes-Brocks syndrome. By contrast, kidney failure has been reported as the presenting feature of Townes-Brocks syndrome on only one occasion. While the SALL1 gene, mutations of which result in the Townes-Brocks phenotype, is expressed in the developing kidney, the absence of other corroborative reports of kidney failure presenting in affected individuals suggests that the solitary observation of kidney failure is as likely due to chance as to causal association. In now reporting a further instance of this association, we review the literature, demonstrating that several other instances of kidney failure are in fact known, despite an incomplete dataset. These findings suggest that kidney failure may be a constituent element of the natural history of Townes-Brocks syndrome and raise the possible benefits of longitudinal survey for progressive kidney impairment in patients with this syndrome.

Hipoacusia en el síndrome de townes-brocks

In nineteen seventy two Towns and Brocks reported on a family in which the father and seven children showed anal atresia, triphalangeal thumb, metatarsal synostosis, extra fingers, neurosensorial deafness and ear abnormalities. The main traits were those related to hand, ear and anus alterations, transmitted under a dominant autosomal pattern. In this paper we present several members of the same family with similar alterations who finally were diagnosed of Townes-Brocks syndrome.

Unique family with Townes-Brocks syndrome, SALL1 mutation, and cardiac defects

Townes-Brocks syndrome (TBS) is a condition with imperforate anus, hand anomalies, and ear malformations with sensorineural hearing loss. Many cases are sporadic. Within and between families, the phenotype displays striking variability. Recently, the disease-causing gene for TBS was identified as SALL1, a zinc finger transcription factor. Here, we report a three-generation family with seven affected individuals who have a novel SALL1 mutation. Unique cardiac anomalies seen in this family include lethal truncus arteriosus in one patient and a lethal complicated defect, including pulmonary valve atresia, in a second patient. These severe cardiac anomalies have not previously been reported in a familial case of TBS. This family and a review of the literature indicate that cardiac evaluation is warranted in all individuals with this disorder. In addition, hypoplastic thumbs were seen in two individuals in this family and should, therefore, be considered a true feature of TBS.

Three-generation family with resemblance to Townes-Brocks syndrome and Goldenhar/oculoauriculovertebral spectrum

The Townes-Brocks syndrome (TBS) is comprised of a triad including characteristic anal, thumb, and ear anomalies. There are many other organ system abnormalities which may be present. However, the literature does not emphasize craniofacial findings except with reference to the typical ear configuration. A three-generation family is described in which craniofacial manifestations were prominent and a Goldenhar-like condition was considered as the most likely diagnosis. However, with the recent birth of an affected male who had an imperforate anus, the diagnosis of TBS was also considered. The family manifests a variety of Goldenhar-like findings, including epibulbar dermoids, hemifacial microsomia, preauricular tags, macrostomia, and micrognathia in addition to classical ear, radial, and anal findings of TBS. We report on this family to point out a possible biological relationship of these two conditions.

Non-cardiac malformations in individuals with outflow tract defects of the heart: the Baltimore-Washington Infant Study (1981-1989)

In the Baltimore-Washington Infant Study, a regional case-control study of 4,390 liveborn infants with cardiovascular malformations (CVM), 642 patients (14.2%) had outflow tract abnormalities, with extracardiac defects in 157 (approximately 25%) of them. Associated defects were found in 1/3 of patients with normal great arteries, but only in 1/10 of patients with transposition of great arteries (TGA). The extracardiac defects were especially rare in the groups "TGA with intact ventricular septum" and "TGA with ventricular septal defect". Patients with multiple associated defects outnumbered patients with isolated associated defects in the ratio 2.5:1. The associated defects were heterogeneous: 46 patients had chromosome abnormalities, 16 had different Mendelian syndromes, and 36 had associations (DiGeorge sequence and VACTERL association were the most frequent). A new syndrome of multiple congenital abnormalities including tetralogy of Fallot, and rare cases of chromosomal and Mendelian syndromes (distal trisomy 1q, tetrasomy 8p, Holzgreve syndrome) are described briefly. Sufficient variability of a spectrum of conotruncal defects in the patients with the same chromosomal or Mendelian syndromes suggests that at least in some cases different conotruncal defects are stages of the same morphologic spectrum. The analysis of conotruncal defects in sibs of patients with Mendelian syndromes may provide new data about the links between different definitive forms of CVM.

Hearing loss in Townes-Brocks syndrome

Townes-Brocks syndrome is an autosomal dominant syndrome consisting of anomalies affecting the ear, hand, foot, anus, and kidney. Anomalies affecting the ear include lop ear, preauricular skin tags, ossicular abnormalities, and a mixed hearing loss. The hearing loss in Townes-Brocks syndrome is predominantly sensorineural, affects high-frequency thresholds more than low-frequency thresholds, and has a variable (usually small) conductive component. The sensorineural component of the hearing loss is slowly progressive. It is typically in the mild range (20 to 40 dB hearing level) during early childhood and progresses to the moderate hearing loss range (40 to 60 dB hearing level) by early adulthood. We present a description of the otologic manifestations and an analysis of audiologic findings in six members of a family with Townes-Brocks syndrome.

Townes-Brocks syndrome in two mentally retarded youngsters

We report on 2 children with Townes-Brocks syndrome (TBS) and mental retardation. One child had mild hearing loss, but the other only had hearing loss at 8000 Hz. These cases suggest that there may be an increased incidence of mental retardation in individuals with TBS.

Townes-Brocks syndrome

A 2-week-old male is presented with the clinical findings of the autosomal dominant Townes-Brocks syndrome in an otherwise unaffected family. The patient showed the full spectrum of anomalies including imperforate anus, perineal fistula, triphalangeal thumb, preaxial polydactyly, pre-auricular tags, and microtia. As there is considerable overlap with the VACTERL association, careful examination of the parents is necessary with regard to the genetic counselling risk.

The Townes-Brocks syndrome

Images

Growth hormone deficiency, wormian bones, dextrocardia, brachycamptodactyly, and other midline defects

We report on a 17-month-old boy with Wormian bones, short stature, growth hormone deficiency, developmental delay, brachycamptodactyly, dextrocardia, cryptorchidism, midshaft hypospadias, hypoplastic left kidney, and imperforate anus. This unique combination of abnormalities has not been reported previously.

A new family with the Townes-Brocks syndrome

We describe a new family with the Townes-Brocks syndrome, a dominantly inherited syndrome of anal, urorenal, ear and limb malformations. The proband shows the full spectrum of anomalies, including imperforate anus, prominent perineal raphe, rectoperineal fistula, triphalangeal thumb, preaxial hexadactyly, syndactyly, clinodactyly, preauricular protuberances, hypoplastic satyr ears, sensorineural hearing loss and urorenal anomalies. In contrast, the father shows only limb anomalies, sensorineural hearing loss and renal anomalies. Anorectal malformations, which are present in almost every patient with the Townes-Brocks syndrome, were absent in the father. This case report illustrates the intrafamilial variability of the Townes-Brocks syndrome. Consequently, careful examination of relatives of patients with this syndrome is necessary for the differential diagnosis with the sporadically inherited VA(C)TER(L) association.