Comparison between isolated ectrodactyly and split hand / split foot as a part of syndromes: Clinical and orodental studies

ABSTRACT

Ectrodactyly is a developmental disorder that describes the partial or total absence of distal segments of the hand with the proximal segments more or less normal. The malformation can occur either isolated or associated with other systemic anomalies as a part of syndromes. Split hand/ split foot malformation [SHFM], associated with syndactyly of digits on both sides of the deficiency, is a longitudinal axial reduction defect, which is also either isolated or as a part of syndromes. This study included 2 patients with isolated ectrodactyly and 6 cases with split hand/split foot as a part of 2 syndromes; 5 of which were consistent with the ectrodactyly, ectodermal dysplasia, cleft lip and palate syndrome [EEC syndrome] and 1 female patient with ectrodactyly, ectodermal dysplasia, macular dystrophy syndrome [EEM syndrome]. Pedigree analysis, detailed physical examination, orodental studies and X-ray examination of hands, feet and teeth were done for all cases. Complete eye evaluation, hearing assessment and pelvi-abdominal ultrasound were carried out for syndromic cases. Chromosomal analysis was done for all patients. Our results showed that the 2 isolated cases with ectrodactyly were unilateral and sporadic with some evidence of multifactorial etiology. Cases with EEC syndrome showed variable degrees of SHFM, manifestations of ectodermal dysplasia in the form of sparse hair, eyebrows and eye lashes, microdontia, dysplastic nails and dry skin in addition to cleft lip and palate. Other orodental features included enamel hypoplasia, xeroderma and tooth decay. Lacrimal duct obstruction, microphthalmia, anophthalmia, photophobia and conjunctivitis were evident ocular manifestations in some cases. All our patients were sporadic with high paternal age in two cases suggesting dominant mutation. In our patient with EEM syndrome macular dystrophy was present in association with ectrodactyly and ectodermal dysplasia in the form of fair sparse hair and eyebrows as well as an albinoid fundus. Being the offspring of consanguineous young parents confirmed the autosomal recessive pattern of inheritance in the EEM syndrome. Chromosomal studies were normal in all studied cases. This study clarifies the importance of meticulous examination of patients with reduction defects and their family members and the search for associated anomalies in order to reach a proper diagnosis and provide accurate genetic counseling. For proper genetic counseling it is also important to clarify the terminology of ectrodactyly as an isolated defect and to differentiate between this sporadic digital anomaly and the inherited split hand/split foot either as an isolated defect or as a part of syndromes