Truncating variants of the sterol recognition region of SHH cause hypertelorism phenotype rather than hypotelorism-holoprosencephaly.

Sonic hedgehog signaling molecule (SHH) is a key molecule in the cilia-mediated signaling pathway and a critical morphogen in embryogenesis. The association between loss-of-function variants of SHH and holoprosencephaly is well established. In mice experiments, reduced or increased signaling of SHH have been shown to be associated with narrowing or excessive expansion of the facial midline, respectively. Herein, we report two unrelated patients with de novo truncating variants of SHH presenting with hypertelorism rather than hypotelorism. The first patient was a 13-year-old girl. Her facial features included hypertelorism, strabismus, telecanthus, malocclusion, frontal bossing, and wide widow's peak. She had borderline developmental delay and agenesis of the corpus callosum. She had a nonsense variant of SHH: Chr7(GRCh38):g.155802987C > T, NM_000193.4:c.1302G > A, p.(Trp434*). The second patient was a 25-year-old girl. Her facial features included hypertelorism and wide widow's peak. She had developmental delay and agenesis of the corpus callosum. She had a frameshift variant of SHH: Chr7(GRCh38):g.155803072_155803074delCGGinsT, NM_000193.4:c.1215_1217delCCGinsA, p.(Asp405Glufs*92). The hypertelorism phenotype contrasts sharply with the prototypical hypotelorism-holoprosencephaly phenotype associated with loss-of-function of SHH. We concluded that a subset of truncating variants of SHH could be associated with hypertelorism rather than hypotelorism.

Detection of ocular hypertelorism among Indian children.

Background & objectives: Ocular hypertelorism constitutes an important component of many clinical syndromes. It is typically recommended to use inter-pupillary distance (IPD) for objective evaluation of ocular hypo/hypertelorism. Barring infancy, there is a scarcity of data on this anthropometric parameter relating to the ocular apparatus. This study aims to study auxological dynamics of IPD in children of Indian origin. Methods: A total of 3622 ( 2239 males and, 1383 females) normal, healthy Indian children of North-western origin, aged one month to 14 yr comprised the sample for this study. Inner and outer-canthal distance were measured using standardized anthropometric techniques. None of the children who participated in this study had craniofacial dysmorphism or any body deformity. Mean (standard deviation SD) and percentiles were calculated for IPD in male and female subjects at different age levels. Results: IPD increased from 4.68±0.21 to 6.19±0.36 cm in males and from 4.59±0.26 to 6.08±0.25 cm in females between one month and 14 yr of age. Boys in general, possessed larger IPD than girls, however, the gender differences became significant (P≤0.05) at 10, 11, 16-18 and 22-24 months, respectively, and five and 10 yr of age, respectively. Interpretation & conclusions: The results of this study suggest that the patients having IPD less than the 3rd percentile should be treated as cases of hypotelorism while, those exceeding 97th percentile as cases of hypertelorism. The use of percentile grids presented for IPD may be used to detect ocular hypotelorism and hypertelorism in male and female children to corroborate diagnosis of different syndromes.

Rare Disease: Lobar Holoprosencephaly With a Median Cleft Lip-Case Report.

Holoprosencephaly is a complex malformation of the brain associated with the median facial defects. Variability of the clinical picture is the characteristic of this anomaly. In most cases, the degree of severity of the facial anomaly correlates with the degree of damage to the brain. This article aims to present a rare case of child with a milder form of brain anomaly combined with a severe form of facial anomaly. The article also presents the application of a feeding stimulator to improve the child's quality of life. The anomaly was diagnosed by postnatal sonography of the brain, magnetic resonance imaging of the endocranium, and three-dimensional computed tomography of the craniofacial skeleton.

Growth Pattern and Use of Inter-pupillary Distance in the Detection of Ocular Hypertelorism and Hypotelorism in Indian Down Syndrome Children.

Use of inter-pupillary distance (IPD) for objective evaluation of ocular hypertelorism and hypotelorism is recommended to corroborate diagnosis of syndromic conditions. In view of complete absence of serial data on growth of IPD, this study aims to unfold auxological dynamics of IPD in Down syndrome (DS) children of Indian origin. Inner canthal distance (ICD) and outer canthal distance (OCD) were measured on a total of 1,125 (male: 752, female: 373) DS children, aged 0 to 3 months to 10 years at 6 monthly age intervals using a "Digimatic Sliding Caliper" in the Growth Laboratory/Growth Clinic of the Institute. Using Feingold and Bossert (1974) formula, IPD at each age was calculated from ICD and OCD measured among male and female DS children. IPD, like OCD and ICD increased un-interruptedly among DS children. IPD grew rapidly up to 5 years thereafter, its rapidity became slower. Boys in general, possessed larger IPD than girls, however, gender differences became statistically significant up to first 4 years of life. Our study children possessed significantly smaller IPD as compared with their normal Indian counterparts. None of our DS children depicted ocular hypertelorism while hypotelorism, was noticed amongst 4.9% male and 16.8% female DS patients. Comparison with normative IPD data failed to establish existence of ocular hypertelorism in DS children (<10 years) of north-western Indian origin. Use of age and gender-specific data presented for IPD of DS children may be made for comparative purpose to ascertain inter-population variability.

A Rare Recurrent 4q25 Proximal Deletion Not Involving the PITX2 Gene: A Genomic Disorder Distinct from Axenfeld-Rieger Syndrome.

Haploinsufficient microdeletions within chromosome 4q25 are often associated with Axenfeld-Rieger syndrome. A de novo 4q25 deletion, 675 kb proximal to PITX2, has previously been reported once in an adult patient. The patient did not have Axenfeld-Rieger anomaly, but instead had intellectual disability and a complex behavioral phenotype with withdrawn, stereotypic, and ritualistic behavior. Array comparative genome hybridization demonstrated a smaller, overlapping 4q25 deletion in a 2-year-old patient and his mother, both having significant phenotypic overlap with the initially reported patient. All 3 patients have distinct facial features (including mild hypotelorism and subtle mandibular asymmetry), developmental delay, and complex behavioral difficulties. A genotype-phenotype correlation narrows the shared phenotype to a common COL25A1 gene aberration and proposes that the concurrent EGF gene loss has a significant impact on the phenotypic severity. Overall, our patients provide data to support the existence of a novel 4q25 proximal deletion syndrome.

Holoprosencephaly with multiple anomalies of the craniofacial bones-an autopsy report.

Holoprosencephaly (HPE), a disorder which results from a failure of cleavage or the incomplete differentiation of the forebrain structures at various levels or to various degrees, is related to hereditary factors, chromosomal anomalies, cytogenetic abnormalities, and environmental teratogenic factors. We are reporting a case of a multiparous woman who was G3,P3,L2, who delivered a full term foetus with holoprosencephaly and multiple craniofacial anomalies. An autopsy was conducted. Multiple anomalies of the craniofacial bones, which include hypoplasia and synostosis of the frontal bone, anophthalmia, absence of the anterior cranial fossa, hypoplasia of the maxillae, an absent antrum, cleft palate, a central hare lip and arrhinia which includes absence of the nostrils and hypotelorism of the eye placodes, were noted. This case is being reported for its rarity and the available literature was reviewed in this respect.

Ethmocephaly with amniotic band syndrome.

Ethmocephaly is the rarest form of holoprosencephaly, which occurs due to an incomplete cleavage of the forebrain. Clinically, the disease presents with a proboscis, hypotelorism, microphthalmos and malformed ears. Amniotic band syndrome is another rare congenital malformation with ring-like constriction bands in the limbs, head, face or trunk. We present a case of ethmocephaly with amniotic band syndrome, which is likely the first of its kind, published in the literature.