Holzgreve syndrome: recurrence in sibs

The genetic etiologies of bilateral renal agenesis

OBJECTIVE

The goal of this study was to review and analyze the medical literature for cases of prenatal and/or postnatally diagnosed bilateral renal agenesis (BRA) and create a comprehensive summary of the genetic etiologies known to be associated with this condition.

METHODS

A literature search was conducted as a scoping review employing Online Mendeliain Inheritance in Man, PubMed, and Cochrane to identify cases of BRA with known underlying genetic (chromosomal vs. single gene) etiologies and those described in syndromes without any known genetic etiology. The cases were further categorized as isolated versus non-isolated, describing additional findings reported prenatally, postnatally, and postmortem. Inheritance pattern was also documented when appropriate in addition to the reported timing of diagnosis and sex.

RESULTS

We identified six cytogenetic abnormalities and 21 genes responsible for 20 single gene disorders associated with BRA. Five genes have been reported to associate with BRA without other renal anomalies; sixteen others associate with both BRA as well as unilateral renal agenesis. Six clinically recognized syndromes/associations were identified with an unknown underlying genetic etiology. Genetic etiologies of BRA are often phenotypically expressed as other urogenital anomalies as well as complex multi-system syndromes.

CONCLUSION

Multiple genetic etiologies of BRA have been described, including cytogenetic abnormalities and monogenic syndromes. The current era of the utilization of exome and genome-wide sequencing is likely to significantly expand our understanding of the underlying genetic architecture of BRA.

Sirenomelia: a new type, showing VACTERL association with Thomas syndrome and a review of literature

Sirenomelia or "mermaid syndrome" is a rare congenital anomaly known since antiquity. This congenital anomaly is defined as a polymalformative syndrome that associates major muscle and skeleton abnormalities (unique lower limbs) with visceral abnormalities (unilateral or bilateral renal agenesis, anomalies of the abdominal vascularisation). This phenotype, typical of sirenomelia syndrome, may be more or less severe. The pathogenic mechanisms of this syndrome are still debated and its etiology remains unknown. We report here a new type of sirenomelia that we observed in a fetus belonging to the collection of the Department of Anatomy of Reims, which led us to perform a comprehensive review of the literature on the subject: this type has never been reported and cannot be classified according to the Stocker and Heifetz classification. Moreover, this case also presents a VACTERL association with Thomas syndrome.

The genetics of hypoplastic left heart syndrome

Hypoplastic left heart syndrome is one of the most therapeutically challenging congenital cardiac defects. It accounts for as many as 1.5% of all congenital heart defects, but is responsible for up to one quarter of deaths in neonates with heart disease.1The management of hypoplastic left heart syndrome is controversial. Two surgical options exist:2,3the Norwood procedure, is a three stage repair in which the morphologically right ventricle is converted to function as the systemic ventricle. Alternatively, orthotopic transplantation can be performed. Although both surgical options have had improved outcomes, the prognosis for long-term survival is guarded, with a five year survival for either approach reported to be in the region of 50–60%. In this review, I explore the evidence for a genetic etiology for the “classic” hypoplastic left heart syndrome, defined as mitral and/or aortic atresia with hypoplasia of the left ventricular cavity and the other left-sided structures.

Thomas syndrome: potter sequence with cleft lip/palate and cardiac anomalies

Holzgreve et al. [Am J Med Genet 18:177-184, 1984] first reported on a syndrome including renal anomalies, heart defect, polydactyly, and cleft palate with other oropharyngeal anomalies. We report here on four sibs with renal adysplasia associated in two with cardiovascular malformations and cleft lip or cleft palate in two. We propose that these patients as the two siblings reported by Thomas et al. [Am J Med Genet 45:767-769, 1993] are affected with a syndrome different of the one described by Holzgreve et al. [Am J Med Genet 18:177-184, 1984] mainly because of the absence of polydactyly. Thomas syndrome is probably inherited as an autosomal recessive trait with marked variability.

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.