Mandibuloacral dysplasia and LMNA A529V mutation in Turkish patients with severe skeletal changes and absent breast development.

Mandibuloacral dysplasia (MAD) is an autosomal recessive disorder characterized by acroosteolysis (resorption of terminal phalanges), skin changes (hyperpigmentation), clavicular hypoplasia, craniofascial anomalies, a hook nose and prominent eyes, delayed closures of the cranial sutures, lipodystrophy, alopecia, and skeletal anomalies. MAD patients are classified according to lipodystrophy patterns: type A and type B. The vast majority of MAD cases are caused by LMNA gene mutations. MAD patients with type A lipodystrophy (MADA) have been reported to have LMNA R527H, A529V, or A529T mutations. In this report, we describe two MADA patients with progressive skeletal changes, absent breast development, and cataract in addition to the classical MAD phenotype. Both patients were found to be homozygous for the Ala529Val mutation of the LMNA gene. Our female patient is the oldest MADA patient (59 years old) who has ever been reported with the LMNA mutation and also the LMNA Ala529Val mutation. This study is the second report on MADA patients with a homozygous Ala529Val mutation.

Prenatally diagnosed case of 22q11.2 deletion syndrome associated with pulmonary artery aneurysm.

Here, we report a new case with chromosome 22q11 deletion and cardiac anomaly diagnosed prenatally by echocardiography. Fluorescence in situ hybridization (FISH) analysis demonstrated a heterozygous deletion at 22q11.2. Echocardiography revealed ventricular septal defect, pulmonary atresia, and aneurysm of the main pulmonary artery and its branches. Pulmonary artery aneurysm (PAA) is rarely seen in patients with 22q11.2 deletion syndrome (22qDS). In this case, PAA was found by prenatal echocardiographic examination at the 25th week of gestation. To date, no prenatally diagnosed case of 22qDS with PAA has been reported. This is the first 22qDS case with PAA that was detected prenatally by FISH analysis.

Familial ring (18) mosaicism in a 23-year-old young adult with 46,XY,r(18) (::p11→q21::)/46,XY karyotype, intellectual disability, motor retardation and single maxillary incisor and in his phenotypically normal mother, karyotype 47,XX,+r(18)(::p11→q21::)/46,XX.

We report on a 23-year-old man with craniofacial findings of the holoprosencephaly spectrum disorder (microcephaly, hypotelorism, depressed nasal bridge, single median maxillary central incisor), fusion of C2-C3 vertebrae, intellectual disability, and severe sleep apnea. Chromosome analysis of blood lymphocytes showed 75% ring (18) cells and 25% normal cells, karyotype mos 46,XY,r(18)(::p11→q21::)[75]/46,XY[25]. His mother was phenotypically normal except for a double ureter and bifid renal pelvis as in his son. She had a supernumerary ring (18) in 10% of blood lymphocytes, karyotype mos 47,XX,+r(18)(::p11→q21::)[10]/46,XX[90]. Familial ring (18) is a rare cytogenetic abnormality. This is the first report of a mother with a supernumerary ring (18) and a son with ring (18) mosaicism. Interestingly, the son showed a true mosaicism (mixoploidy) of ring (18) and normal cells. The mother's 46,XX cells could be easily explained by mitotic instability and ring loss during cell division. However, the coexistence of ring (18) and normal cells in the son is unusual. Possibly, during early postzygotic divisions of a 47,XY,+r(18) zygote, two (possibly subsequent) genetic events could have occurred, one when one normal chromosome 18 was lost (resulting in a cell line with ring 18), and one when the ring 18 was lost (resulting in a cell line without ring, "escape to normal"). Alternatively, the zygote of the son could have been 46,XY,r(18), and postzygotic loss of the ring 18 could have resulted in monosomy 18 cells followed by duplication of chromosome 18 in these cells (a rare mechanism for cell survival previously described as "compensatory" isodisomy).

Disruption of ALX1 causes extreme microphthalmia and severe facial clefting: expanding the spectrum of autosomal-recessive ALX-related frontonasal dysplasia.

We present an autosomal-recessive frontonasal dysplasia (FND) characterized by bilateral extreme microphthalmia, bilateral oblique facial cleft, complete cleft palate, hypertelorism, wide nasal bridge with hypoplasia of the ala nasi, and low-set, posteriorly rotated ears in two distinct families. Using Affymetrix 250K SNP array genotyping and homozygosity mapping, we mapped this clinical entity to chromosome 12q21. In one of the families, three siblings were affected, and CNV analysis of the critical region showed a homozygous 3.7 Mb deletion containing the ALX1 (CART1) gene, which encodes the aristaless-like homeobox 1 transcription factor. In the second family we identified a homozygous donor-splice-site mutation (c.531+1G > A) in the ALX1 gene, providing evidence that complete loss of function of ALX1 protein causes severe disruption of early craniofacial development. Unlike loss of its murine ortholog, loss of human ALX1 does not result in neural-tube defects; however, it does severely affect the orchestrated fusion between frontonasal, nasomedial, nasolateral, and maxillary processes during early-stage embryogenesis. This study further expands the spectrum of the recently recognized autosomal-recessive ALX-related FND phenotype in humans.

A specific mutation in the distant sonic hedgehog (SHH) cis-regulator (ZRS) causes Werner mesomelic syndrome (WMS) while complete ZRS duplications underlie Haas type polysyndactyly and preaxial polydactyly (PPD) with or without triphalangeal thumb.

Werner mesomelic syndrome (WMS) is an autosomal dominant disorder with unknown molecular etiology characterized by hypo- or aplasia of the tibiae in addition to the preaxial polydactyly (PPD) of the hands and feet and/or five-fingered hand with absence of thumbs. We show that point mutations of a specific nucleotide within the sonic hedgehog (SHH) regulatory region (ZRS) cause WMS. In a previously unpublished WMS family, we identified the causative G>A transition at position 404 of the ZRS, and in six affected family members of a second WMS family we found a 404G>C mutation of the ZRS. The 404G>A ZRS mutation is known as the "Cuban mutation" of PPD type II (PPD2). Interestingly, the index patient of that family had tibial hypoplasia as well. These data provide the first evidence that WMS is caused by a specific ZRS mutation, which leads to strong ectopic SHH expression. In contrast, we show that complete duplications of the ZRS region lead to type Haas polysyndactyly or triphalangeal thumb-polysyndactyly syndrome, but do not affect lower limb development. We suggest the term "ZRS-associated syndromes" and a clinical subclassification for the continuum of limb malformations caused by different molecular alterations of the ZRS.

Characterization of double ring chromosome 4 mosaicism associated with bilateral hip dislocation, cortical dysgenesis, and epilepsy.

We present the clinical and molecular findings in a Turkish child with a de novo mosaic ring derived from chromosome 4 with multiple cell-lines; the karyotype was 46,XY,r(4)[83]/45,XY, -4[6]/47,XY,r(4),+r(4)[5]/48,XY,r(4),+r(4),+dic r(4)[1]/46,XY[5]. The patient is a 20-month-old male who was the first pregnancy of nonconsanguineous parents. The baby was delivered at term with a birth weight of 1,700 g (<3rd centile) and a length of 46 cm. The baby had feeding difficulties and vomiting problems. He started walking at age 2 years and delayed language was observed. Facial appearance was normal, but the ears were large with abnormal structure. The hands showed bilateral clinodactyly of the 5th fingers. He had mild mental retardation, and epilepsy. Analysis of chromosomes showed 46,XY,r(4)(::p16.3 --> qter::)[67]/46,XY,r(4;4)(::p16.3 --> qter::p16.3 --> qter::)[2]/46,XY[3] by multicolor banding (MCB) technique. Array CGH delineated the size of the terminal deletion as 900 kb in 4p16.3. The Wolf-Hirschhorn critical region was preserved even though our patient had mild mental and motor retardation. While the mosaicism of the ring 4 could affect the phenotype, the deleted 900 kb distal deletion and clinical features of the patient may provide further insight into characteristic phenotype of the 4p- related syndromes.

Early prenatal diagnosis of conjoined twins at 7 weeks and 6 days' gestation with two-dimensional Doppler ultrasound: a case report.

This case report presents the prenatal diagnosis of conjoined twins at 7 weeks and 6 days' gestation according to the last menstrual period and 6 weeks and 4 days' gestation according to crown-rump length in a 32-year-old Turkish woman, using two-dimensional Doppler ultrasound. The twins were fused to each other at the thoracic region (thoracopagus). In the light of previous reports of conjoined twins this appears to be one of the earliest prenatally diagnosed cases in the medical literature.

A 19-year follow-up of a patient with type 3 ectrodactyly-ectodermal dysplasia-clefting syndrome who developed non-Hodgkin lymphoma.

The ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome is characterized by ectrodactyly, ectodermal dysplasia, and clefting. The development of a malignancy with EEC syndrome is very rare. Here we present follow-up on a Turkish boy with EEC syndrome type 3 who developed malignant lymphoma with high expression of p63. He had chronic renal failure due to recurrent urinary infections caused by ureterovesical reflux. Cervical, diffuse, large, B-cell non-Hodgkin lymphoma with high expression of p63 was diagnosed, and the patient died at 19 years of age. The transcription factor p63 is a key regulator of ectodermal, orofacial, and limb development. Mutations in the p63 gene can cause syndromes of ectodermal dysplasia, ectrodactyly, and orofacial clefting. Malignant lymphoma is a very rare complication of EEC syndrome. We suggest that p63 gene mutation analysis should be performed in every EEC syndrome patient with the possibility of developing malignant tumors.

ALX4 dysfunction disrupts craniofacial and epidermal development.

Genetic control of craniofacial morphogenesis requires a complex interaction of numerous genes encoding factors essential for patterning and differentiation. We present two Turkish families with a new autosomal recessive frontofacial dysostosis syndrome characterized by total alopecia, a large skull defect, coronal craniosynostosis, hypertelorism, severely depressed nasal bridge and ridge, bifid nasal tip, hypogonadism, callosal body agenesis and mental retardation. Using homozygosity mapping, we mapped the entity to chromosome 11p11.2-q12.3 and subsequently identified a homozygous c.793C-->T nonsense mutation in the human ortholog of the mouse aristaless-like homeobox 4 (ALX4) gene. This mutation is predicted to result in a premature stop codon (p.R265X) of ALX4 truncating 146 amino acids of the protein including a part of the highly conserved homeodomain and the C-terminal paired tail domain. Although the RNA is stable and not degraded by nonsense-mediated RNA decay, the mutant protein is likely to be non-functional. In a skin biopsy of an affected individual, we observed a hypomorphic interfollicular epidermis with reduced suprabasal layers associated with impaired interfollicular epidermal differentiation. Hair follicle-like structures were present but showed altered differentiation. Our data indicate that ALX4 plays a critical role both in craniofacial development as in skin and hair follicle development in human.

Selective feticide in dichorionic pregnancies with intracardiac blood aspiration: report of nine cases.

In a twin pregnancy discordant for a chromosomal or structural abnormality, the family is faced with two alternatives: expectant management or selective feticide of the abnormal fetus. Methods of selective feticide differ according to chorionicity due to the presence of intertwin anastomoses in monochorionic placentas. Intracardiac KCl injection is commonly used in dichorionic pregnancies. Here, we describe an alternative method for selective feticide in dichorionic pregnancies by blood aspiration from the fetal heart until cardiac arrest.

Prenatally diagnosed lethal type Larsen-like syndrome associated with bifid tongue.

Larsen syndrome is characterized by multiple joint dislocations, associated with a typical facial appearance and frequently other abnormalities. Both dominant and recessive patterns of inheritance have been reported. A lethal form of Larsen syndrome (Larsen-like syndrome) has been described as a combination of the Larsen phenotype and pulmonary hypoplasia. In this report, we present a 24-week-old female fetus with a possible prenatal diagnosis of thanatophoric dysplasia in whom postmortem examination revealed lethal type Larsen-like syndrome associated with bifid tongue, severe micrognathia and non-immune hydrops fetalis. These findings have not been reported previously in the lethal type Larsen syndrome.

Association of assisted reproductive technology with twinning and congenital anomalies.

Recently many reports have been published on the use of intracytoplasmic sperm injection (ICSI) and the increased risk of congenital major malformations or syndromes. We present three cases with Goldenhar syndrome (one of them a twin pair) and one case with Rubinstein-Taybi syndrome (RTS), also a twin pair. All four female cases are derived from ICSI. Goldenhar syndrome with ICSI pregnancy has been reported previously but as far as we know, RTS has not been described in association with assisted reproductive technology (ART). The four new cases reported herein will contribute to a better understanding whether ICSI pregnancy increases congenital malformations.

Rubinstein-Taybi syndrome with normal FISH result and CREBBP gene analysis: a case report.

We report on a six-year-old boy with typical Rubinstein-Taybi syndrome (RSTS) phenotype. Clinical findings included mental and motor retardation, patent ductus arteriosus (PDA), undescended testes, hirsutism, broad thumbs with radial angulation and broad toes, and inguinal hernia. His karyotype was normal (46, XY) and fluorescence in situ hybridization (FISH) showed no deletion of the CREBBP [cAMP response element-binding (CREB) binding protein] gene on chromosome 16p13.3. CREBBP gene sequencing also revealed normal results. We wish to present this case because this patient had typical RSTS phenotype, but normal FISH and CREBBP gene sequencing results. It could be possible that genetic heterogeneity is related with novel mutations in other genes. With the publication of such cases, their significance will be brought to the attention of researchers in this field.