Two Rare Syndromic Syndactyly Cases in Neonates

Introduction Isolated findings of syndactyly are benign. However, syndactyly can be associated with rare syndromes that need to be diagnosed for further management and for genetic counseling. Methods We present two cases of syndromic syndactyly in neonates. The first case is a 13-day-old female neonate with dysmorphic features. The neonate had clinical features of prominent forehead, hypertelorism, widely separated sagittal and metopic sutures, down-slanting eyes, low set ears, depressed nasal bridge, micrognathia, cleft palate, pectus excavatum, brachydactyly, and syndactyly of the second to fourth fingers bilaterally in upper limbs and in lower limbs.The second case is a 10-day-old male neonate with dysmorphism in the form of cleft alveolar ridge and palate, hyperplastic frenula, hypoplastic alar cartilage, syndactyly of the left hand, clinodactyly of the left lower limb toes, and amniotic bands. Discussion Case 1 was diagnosed as otopalatodigital syndrome because of the characteristic clinical features. This is a rare syndrome associated with syndactyly that often goes undiagnosed. Otopalatodigital syndrome spectrum disorders comprise of four phenotypically related conditions: otopalatodigital syndrome types 1 and 2, frontometaphyseal dysplasia, and Melnick–Needles syndrome. As it is associated with x-linked inheritance, its severity is more in males.Case 2 was diagnosed to have orofaciodigital syndrome because of the characteristic clinical features. It is another rare syndrome associated with syndactyly having abnormalities in the development of the oral cavity, face, and digits along with intellectual disability and renal system impairment. Conclusion There are fewer publications on these syndromes as they are rare and diagnosis is difficult. Recognizing these syndromes is key to further management and for genetic counseling.

Otopalatodigital syndrome type I: novel characteristics and prenatal manifestations in two siblings

Otopalatodigital spectrum disorder (OPDSD) is rare group of X-linked disorders caused by mutations in the filamin A (FLNA) gene. It is characterized by skeletal dysplasia of variable severity and different extra skeletal manifestations. Its presentation in the fetal period is quite unspecific, so diagnosis is usually made after birth. We present prenatal ultrasonography and postmortem findings that led us to a diagnosis of the mildest form of OPDSD (OPD type I) in two consecutive pregnancies. This is the first report on prenatal diagnosis (PND) of OPD type I. Affected fetuses showed facial dysmorphy (hypertelorism, micrognathia, cleft palate) and digital anomalies, features typical of OPD type I. In addition, microphtalmia and early neonatal death due to severe respiratory distress syndrome are described as a novel characteristics of the disorder. Clinical exome sequencing revealed a hemizygous missense pathogenic variant in the FLNA gene (NM_ 001110556.1: c.620C>T). We suggest that the presence of hypertelorism, micrognathia, digital anomalies on prenatal ultrasound examination should alert suspicion to OPDSD. Detailed clinical examination of mother and other female relatives is of great importance in establishing definitive diagnosis of OPD type I.

Filamin-Associated Dysplasias/Dysostoses and Related Disorders

This chapter discusses filamin-associated dysplasias/dysostoses and related disorders and includes discussion on otopalatodigital syndrome type 1, otopalatodigital syndrome type II, Melnick-Needles osteodysplasty, frontometaphyseal dysplasia, boomerang dysplasia/atelosteogenesis type I, atelosteogenesis type III, Larsen syndrome (autosomal dominant), spondylocarpotarsal synostosis syndrome, and Frank-ter Haar syndrome. Each discussion includes major radiographic features, major clinical findings, genetics, major differential diagnoses, and a bibliography.